Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2 | Linux Ethernet Bonding Driver HOWTO |
| 3 | |
Ben Hutchings | ad246c9 | 2011-04-26 15:25:52 +0000 | [diff] [blame] | 4 | Latest update: 27 April 2011 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | |
| 6 | Initial release : Thomas Davis <tadavis at lbl.gov> |
| 7 | Corrections, HA extensions : 2000/10/03-15 : |
| 8 | - Willy Tarreau <willy at meta-x.org> |
| 9 | - Constantine Gavrilov <const-g at xpert.com> |
| 10 | - Chad N. Tindel <ctindel at ieee dot org> |
| 11 | - Janice Girouard <girouard at us dot ibm dot com> |
| 12 | - Jay Vosburgh <fubar at us dot ibm dot com> |
| 13 | |
| 14 | Reorganized and updated Feb 2005 by Jay Vosburgh |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 15 | Added Sysfs information: 2006/04/24 |
| 16 | - Mitch Williams <mitch.a.williams at intel.com> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 18 | Introduction |
| 19 | ============ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 21 | The Linux bonding driver provides a method for aggregating |
| 22 | multiple network interfaces into a single logical "bonded" interface. |
| 23 | The behavior of the bonded interfaces depends upon the mode; generally |
| 24 | speaking, modes provide either hot standby or load balancing services. |
| 25 | Additionally, link integrity monitoring may be performed. |
| 26 | |
| 27 | The bonding driver originally came from Donald Becker's |
| 28 | beowulf patches for kernel 2.0. It has changed quite a bit since, and |
| 29 | the original tools from extreme-linux and beowulf sites will not work |
| 30 | with this version of the driver. |
| 31 | |
| 32 | For new versions of the driver, updated userspace tools, and |
| 33 | who to ask for help, please follow the links at the end of this file. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | |
| 35 | Table of Contents |
| 36 | ================= |
| 37 | |
| 38 | 1. Bonding Driver Installation |
| 39 | |
| 40 | 2. Bonding Driver Options |
| 41 | |
| 42 | 3. Configuring Bonding Devices |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 43 | 3.1 Configuration with Sysconfig Support |
| 44 | 3.1.1 Using DHCP with Sysconfig |
| 45 | 3.1.2 Configuring Multiple Bonds with Sysconfig |
| 46 | 3.2 Configuration with Initscripts Support |
| 47 | 3.2.1 Using DHCP with Initscripts |
| 48 | 3.2.2 Configuring Multiple Bonds with Initscripts |
| 49 | 3.3 Configuring Bonding Manually with Ifenslave |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 50 | 3.3.1 Configuring Multiple Bonds Manually |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 51 | 3.4 Configuring Bonding Manually via Sysfs |
Nicolas de Pesloüan | de221bd | 2011-01-24 13:21:37 +0000 | [diff] [blame] | 52 | 3.5 Configuration with Interfaces Support |
| 53 | 3.6 Overriding Configuration for Special Cases |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 55 | 4. Querying Bonding Configuration |
| 56 | 4.1 Bonding Configuration |
| 57 | 4.2 Network Configuration |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 59 | 5. Switch Configuration |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 61 | 6. 802.1q VLAN Support |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 63 | 7. Link Monitoring |
| 64 | 7.1 ARP Monitor Operation |
| 65 | 7.2 Configuring Multiple ARP Targets |
| 66 | 7.3 MII Monitor Operation |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 67 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 68 | 8. Potential Trouble Sources |
| 69 | 8.1 Adventures in Routing |
| 70 | 8.2 Ethernet Device Renaming |
| 71 | 8.3 Painfully Slow Or No Failed Link Detection By Miimon |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 72 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 73 | 9. SNMP agents |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 75 | 10. Promiscuous mode |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 77 | 11. Configuring Bonding for High Availability |
| 78 | 11.1 High Availability in a Single Switch Topology |
| 79 | 11.2 High Availability in a Multiple Switch Topology |
| 80 | 11.2.1 HA Bonding Mode Selection for Multiple Switch Topology |
| 81 | 11.2.2 HA Link Monitoring for Multiple Switch Topology |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 83 | 12. Configuring Bonding for Maximum Throughput |
| 84 | 12.1 Maximum Throughput in a Single Switch Topology |
| 85 | 12.1.1 MT Bonding Mode Selection for Single Switch Topology |
| 86 | 12.1.2 MT Link Monitoring for Single Switch Topology |
| 87 | 12.2 Maximum Throughput in a Multiple Switch Topology |
| 88 | 12.2.1 MT Bonding Mode Selection for Multiple Switch Topology |
| 89 | 12.2.2 MT Link Monitoring for Multiple Switch Topology |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 91 | 13. Switch Behavior Issues |
| 92 | 13.1 Link Establishment and Failover Delays |
| 93 | 13.2 Duplicated Incoming Packets |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 94 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 95 | 14. Hardware Specific Considerations |
| 96 | 14.1 IBM BladeCenter |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 97 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 98 | 15. Frequently Asked Questions |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 99 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 100 | 16. Resources and Links |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | |
| 102 | |
| 103 | 1. Bonding Driver Installation |
| 104 | ============================== |
| 105 | |
| 106 | Most popular distro kernels ship with the bonding driver |
Cong Wang | b1098bb | 2013-05-27 15:49:16 +0000 | [diff] [blame] | 107 | already available as a module. If your distro does not, or you |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | have need to compile bonding from source (e.g., configuring and |
| 109 | installing a mainline kernel from kernel.org), you'll need to perform |
| 110 | the following steps: |
| 111 | |
| 112 | 1.1 Configure and build the kernel with bonding |
| 113 | ----------------------------------------------- |
| 114 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 115 | The current version of the bonding driver is available in the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | drivers/net/bonding subdirectory of the most recent kernel source |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 117 | (which is available on http://kernel.org). Most users "rolling their |
| 118 | own" will want to use the most recent kernel from kernel.org. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | |
| 120 | Configure kernel with "make menuconfig" (or "make xconfig" or |
| 121 | "make config"), then select "Bonding driver support" in the "Network |
| 122 | device support" section. It is recommended that you configure the |
| 123 | driver as module since it is currently the only way to pass parameters |
| 124 | to the driver or configure more than one bonding device. |
| 125 | |
Cong Wang | b1098bb | 2013-05-27 15:49:16 +0000 | [diff] [blame] | 126 | Build and install the new kernel and modules. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | |
Cong Wang | b1098bb | 2013-05-27 15:49:16 +0000 | [diff] [blame] | 128 | 1.2 Bonding Control Utility |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 129 | ------------------------------------- |
| 130 | |
Cong Wang | b1098bb | 2013-05-27 15:49:16 +0000 | [diff] [blame] | 131 | It is recommended to configure bonding via iproute2 (netlink) |
| 132 | or sysfs, the old ifenslave control utility is obsolete. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | |
| 134 | 2. Bonding Driver Options |
| 135 | ========================= |
| 136 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 137 | Options for the bonding driver are supplied as parameters to the |
| 138 | bonding module at load time, or are specified via sysfs. |
| 139 | |
| 140 | Module options may be given as command line arguments to the |
| 141 | insmod or modprobe command, but are usually specified in either the |
Lucas De Marchi | 970e248 | 2012-03-30 13:37:16 -0700 | [diff] [blame] | 142 | /etc/modrobe.d/*.conf configuration files, or in a distro-specific |
| 143 | configuration file (some of which are detailed in the next section). |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 144 | |
| 145 | Details on bonding support for sysfs is provided in the |
| 146 | "Configuring Bonding Manually via Sysfs" section, below. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 147 | |
| 148 | The available bonding driver parameters are listed below. If a |
| 149 | parameter is not specified the default value is used. When initially |
| 150 | configuring a bond, it is recommended "tail -f /var/log/messages" be |
| 151 | run in a separate window to watch for bonding driver error messages. |
| 152 | |
| 153 | It is critical that either the miimon or arp_interval and |
| 154 | arp_ip_target parameters be specified, otherwise serious network |
| 155 | degradation will occur during link failures. Very few devices do not |
| 156 | support at least miimon, so there is really no reason not to use it. |
| 157 | |
| 158 | Options with textual values will accept either the text name |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 159 | or, for backwards compatibility, the option value. E.g., |
| 160 | "mode=802.3ad" and "mode=4" set the same mode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | |
| 162 | The parameters are as follows: |
| 163 | |
Nicolas de Pesloüan | 1ba9ac7 | 2011-12-26 13:35:24 +0000 | [diff] [blame] | 164 | active_slave |
| 165 | |
| 166 | Specifies the new active slave for modes that support it |
| 167 | (active-backup, balance-alb and balance-tlb). Possible values |
| 168 | are the name of any currently enslaved interface, or an empty |
| 169 | string. If a name is given, the slave and its link must be up in order |
| 170 | to be selected as the new active slave. If an empty string is |
| 171 | specified, the current active slave is cleared, and a new active |
| 172 | slave is selected automatically. |
| 173 | |
| 174 | Note that this is only available through the sysfs interface. No module |
| 175 | parameter by this name exists. |
| 176 | |
| 177 | The normal value of this option is the name of the currently |
| 178 | active slave, or the empty string if there is no active slave or |
| 179 | the current mode does not use an active slave. |
| 180 | |
Jay Vosburgh | fd989c8 | 2008-11-04 17:51:16 -0800 | [diff] [blame] | 181 | ad_select |
| 182 | |
| 183 | Specifies the 802.3ad aggregation selection logic to use. The |
| 184 | possible values and their effects are: |
| 185 | |
| 186 | stable or 0 |
| 187 | |
| 188 | The active aggregator is chosen by largest aggregate |
| 189 | bandwidth. |
| 190 | |
| 191 | Reselection of the active aggregator occurs only when all |
| 192 | slaves of the active aggregator are down or the active |
| 193 | aggregator has no slaves. |
| 194 | |
| 195 | This is the default value. |
| 196 | |
| 197 | bandwidth or 1 |
| 198 | |
| 199 | The active aggregator is chosen by largest aggregate |
| 200 | bandwidth. Reselection occurs if: |
| 201 | |
| 202 | - A slave is added to or removed from the bond |
| 203 | |
| 204 | - Any slave's link state changes |
| 205 | |
| 206 | - Any slave's 802.3ad association state changes |
| 207 | |
Matt LaPlante | 19f5946 | 2009-04-27 15:06:31 +0200 | [diff] [blame] | 208 | - The bond's administrative state changes to up |
Jay Vosburgh | fd989c8 | 2008-11-04 17:51:16 -0800 | [diff] [blame] | 209 | |
| 210 | count or 2 |
| 211 | |
| 212 | The active aggregator is chosen by the largest number of |
| 213 | ports (slaves). Reselection occurs as described under the |
| 214 | "bandwidth" setting, above. |
| 215 | |
| 216 | The bandwidth and count selection policies permit failover of |
| 217 | 802.3ad aggregations when partial failure of the active aggregator |
| 218 | occurs. This keeps the aggregator with the highest availability |
| 219 | (either in bandwidth or in number of ports) active at all times. |
| 220 | |
| 221 | This option was added in bonding version 3.4.0. |
| 222 | |
Nicolas de Pesloüan | 025890b | 2011-08-06 07:06:39 +0000 | [diff] [blame] | 223 | all_slaves_active |
| 224 | |
| 225 | Specifies that duplicate frames (received on inactive ports) should be |
| 226 | dropped (0) or delivered (1). |
| 227 | |
| 228 | Normally, bonding will drop duplicate frames (received on inactive |
| 229 | ports), which is desirable for most users. But there are some times |
| 230 | it is nice to allow duplicate frames to be delivered. |
| 231 | |
| 232 | The default value is 0 (drop duplicate frames received on inactive |
| 233 | ports). |
| 234 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | arp_interval |
| 236 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 237 | Specifies the ARP link monitoring frequency in milliseconds. |
Jay Vosburgh | f5b2b96 | 2006-09-22 21:54:53 -0700 | [diff] [blame] | 238 | |
| 239 | The ARP monitor works by periodically checking the slave |
| 240 | devices to determine whether they have sent or received |
| 241 | traffic recently (the precise criteria depends upon the |
| 242 | bonding mode, and the state of the slave). Regular traffic is |
| 243 | generated via ARP probes issued for the addresses specified by |
| 244 | the arp_ip_target option. |
| 245 | |
| 246 | This behavior can be modified by the arp_validate option, |
| 247 | below. |
| 248 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 249 | If ARP monitoring is used in an etherchannel compatible mode |
| 250 | (modes 0 and 2), the switch should be configured in a mode |
| 251 | that evenly distributes packets across all links. If the |
| 252 | switch is configured to distribute the packets in an XOR |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | fashion, all replies from the ARP targets will be received on |
| 254 | the same link which could cause the other team members to |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 255 | fail. ARP monitoring should not be used in conjunction with |
| 256 | miimon. A value of 0 disables ARP monitoring. The default |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | value is 0. |
| 258 | |
| 259 | arp_ip_target |
| 260 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 261 | Specifies the IP addresses to use as ARP monitoring peers when |
| 262 | arp_interval is > 0. These are the targets of the ARP request |
| 263 | sent to determine the health of the link to the targets. |
| 264 | Specify these values in ddd.ddd.ddd.ddd format. Multiple IP |
| 265 | addresses must be separated by a comma. At least one IP |
| 266 | address must be given for ARP monitoring to function. The |
| 267 | maximum number of targets that can be specified is 16. The |
| 268 | default value is no IP addresses. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 269 | |
Jay Vosburgh | f5b2b96 | 2006-09-22 21:54:53 -0700 | [diff] [blame] | 270 | arp_validate |
| 271 | |
| 272 | Specifies whether or not ARP probes and replies should be |
Veaceslav Falico | 52f65ef | 2014-02-18 07:48:41 +0100 | [diff] [blame] | 273 | validated in any mode that supports arp monitoring, or whether |
| 274 | non-ARP traffic should be filtered (disregarded) for link |
| 275 | monitoring purposes. |
Jay Vosburgh | f5b2b96 | 2006-09-22 21:54:53 -0700 | [diff] [blame] | 276 | |
| 277 | Possible values are: |
| 278 | |
| 279 | none or 0 |
| 280 | |
Veaceslav Falico | 52f65ef | 2014-02-18 07:48:41 +0100 | [diff] [blame] | 281 | No validation or filtering is performed. |
Jay Vosburgh | f5b2b96 | 2006-09-22 21:54:53 -0700 | [diff] [blame] | 282 | |
| 283 | active or 1 |
| 284 | |
| 285 | Validation is performed only for the active slave. |
| 286 | |
| 287 | backup or 2 |
| 288 | |
| 289 | Validation is performed only for backup slaves. |
| 290 | |
| 291 | all or 3 |
| 292 | |
| 293 | Validation is performed for all slaves. |
| 294 | |
Veaceslav Falico | 52f65ef | 2014-02-18 07:48:41 +0100 | [diff] [blame] | 295 | filter or 4 |
Jay Vosburgh | f5b2b96 | 2006-09-22 21:54:53 -0700 | [diff] [blame] | 296 | |
Veaceslav Falico | 52f65ef | 2014-02-18 07:48:41 +0100 | [diff] [blame] | 297 | Filtering is applied to all slaves. No validation is |
| 298 | performed. |
Veaceslav Falico | d7d35c6 | 2013-06-24 11:49:33 +0200 | [diff] [blame] | 299 | |
Veaceslav Falico | 52f65ef | 2014-02-18 07:48:41 +0100 | [diff] [blame] | 300 | filter_active or 5 |
| 301 | |
| 302 | Filtering is applied to all slaves, validation is performed |
| 303 | only for the active slave. |
| 304 | |
| 305 | filter_backup or 6 |
| 306 | |
| 307 | Filtering is applied to all slaves, validation is performed |
| 308 | only for backup slaves. |
| 309 | |
| 310 | Validation: |
| 311 | |
| 312 | Enabling validation causes the ARP monitor to examine the incoming |
| 313 | ARP requests and replies, and only consider a slave to be up if it |
| 314 | is receiving the appropriate ARP traffic. |
| 315 | |
| 316 | For an active slave, the validation checks ARP replies to confirm |
| 317 | that they were generated by an arp_ip_target. Since backup slaves |
| 318 | do not typically receive these replies, the validation performed |
| 319 | for backup slaves is on the broadcast ARP request sent out via the |
| 320 | active slave. It is possible that some switch or network |
| 321 | configurations may result in situations wherein the backup slaves |
| 322 | do not receive the ARP requests; in such a situation, validation |
| 323 | of backup slaves must be disabled. |
| 324 | |
| 325 | The validation of ARP requests on backup slaves is mainly helping |
| 326 | bonding to decide which slaves are more likely to work in case of |
| 327 | the active slave failure, it doesn't really guarantee that the |
| 328 | backup slave will work if it's selected as the next active slave. |
| 329 | |
| 330 | Validation is useful in network configurations in which multiple |
| 331 | bonding hosts are concurrently issuing ARPs to one or more targets |
| 332 | beyond a common switch. Should the link between the switch and |
| 333 | target fail (but not the switch itself), the probe traffic |
| 334 | generated by the multiple bonding instances will fool the standard |
| 335 | ARP monitor into considering the links as still up. Use of |
| 336 | validation can resolve this, as the ARP monitor will only consider |
| 337 | ARP requests and replies associated with its own instance of |
| 338 | bonding. |
| 339 | |
| 340 | Filtering: |
| 341 | |
| 342 | Enabling filtering causes the ARP monitor to only use incoming ARP |
| 343 | packets for link availability purposes. Arriving packets that are |
| 344 | not ARPs are delivered normally, but do not count when determining |
| 345 | if a slave is available. |
| 346 | |
| 347 | Filtering operates by only considering the reception of ARP |
| 348 | packets (any ARP packet, regardless of source or destination) when |
| 349 | determining if a slave has received traffic for link availability |
| 350 | purposes. |
| 351 | |
| 352 | Filtering is useful in network configurations in which significant |
| 353 | levels of third party broadcast traffic would fool the standard |
| 354 | ARP monitor into considering the links as still up. Use of |
| 355 | filtering can resolve this, as only ARP traffic is considered for |
| 356 | link availability purposes. |
Jay Vosburgh | f5b2b96 | 2006-09-22 21:54:53 -0700 | [diff] [blame] | 357 | |
| 358 | This option was added in bonding version 3.1.0. |
| 359 | |
Veaceslav Falico | 8599b52 | 2013-06-24 11:49:34 +0200 | [diff] [blame] | 360 | arp_all_targets |
| 361 | |
| 362 | Specifies the quantity of arp_ip_targets that must be reachable |
| 363 | in order for the ARP monitor to consider a slave as being up. |
| 364 | This option affects only active-backup mode for slaves with |
| 365 | arp_validation enabled. |
| 366 | |
| 367 | Possible values are: |
| 368 | |
| 369 | any or 0 |
| 370 | |
| 371 | consider the slave up only when any of the arp_ip_targets |
| 372 | is reachable |
| 373 | |
| 374 | all or 1 |
| 375 | |
| 376 | consider the slave up only when all of the arp_ip_targets |
| 377 | are reachable |
| 378 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | downdelay |
| 380 | |
| 381 | Specifies the time, in milliseconds, to wait before disabling |
| 382 | a slave after a link failure has been detected. This option |
| 383 | is only valid for the miimon link monitor. The downdelay |
| 384 | value should be a multiple of the miimon value; if not, it |
| 385 | will be rounded down to the nearest multiple. The default |
| 386 | value is 0. |
| 387 | |
Jay Vosburgh | dd957c5 | 2007-10-09 19:57:24 -0700 | [diff] [blame] | 388 | fail_over_mac |
| 389 | |
| 390 | Specifies whether active-backup mode should set all slaves to |
Jay Vosburgh | 3915c1e8 | 2008-05-17 21:10:14 -0700 | [diff] [blame] | 391 | the same MAC address at enslavement (the traditional |
| 392 | behavior), or, when enabled, perform special handling of the |
| 393 | bond's MAC address in accordance with the selected policy. |
Jay Vosburgh | dd957c5 | 2007-10-09 19:57:24 -0700 | [diff] [blame] | 394 | |
Jay Vosburgh | 3915c1e8 | 2008-05-17 21:10:14 -0700 | [diff] [blame] | 395 | Possible values are: |
Jay Vosburgh | dd957c5 | 2007-10-09 19:57:24 -0700 | [diff] [blame] | 396 | |
Jay Vosburgh | 3915c1e8 | 2008-05-17 21:10:14 -0700 | [diff] [blame] | 397 | none or 0 |
Jay Vosburgh | dd957c5 | 2007-10-09 19:57:24 -0700 | [diff] [blame] | 398 | |
Jay Vosburgh | 3915c1e8 | 2008-05-17 21:10:14 -0700 | [diff] [blame] | 399 | This setting disables fail_over_mac, and causes |
| 400 | bonding to set all slaves of an active-backup bond to |
| 401 | the same MAC address at enslavement time. This is the |
| 402 | default. |
Jay Vosburgh | dd957c5 | 2007-10-09 19:57:24 -0700 | [diff] [blame] | 403 | |
Jay Vosburgh | 3915c1e8 | 2008-05-17 21:10:14 -0700 | [diff] [blame] | 404 | active or 1 |
Jay Vosburgh | dd957c5 | 2007-10-09 19:57:24 -0700 | [diff] [blame] | 405 | |
Jay Vosburgh | 3915c1e8 | 2008-05-17 21:10:14 -0700 | [diff] [blame] | 406 | The "active" fail_over_mac policy indicates that the |
| 407 | MAC address of the bond should always be the MAC |
| 408 | address of the currently active slave. The MAC |
| 409 | address of the slaves is not changed; instead, the MAC |
| 410 | address of the bond changes during a failover. |
| 411 | |
| 412 | This policy is useful for devices that cannot ever |
| 413 | alter their MAC address, or for devices that refuse |
| 414 | incoming broadcasts with their own source MAC (which |
| 415 | interferes with the ARP monitor). |
| 416 | |
| 417 | The down side of this policy is that every device on |
| 418 | the network must be updated via gratuitous ARP, |
| 419 | vs. just updating a switch or set of switches (which |
| 420 | often takes place for any traffic, not just ARP |
| 421 | traffic, if the switch snoops incoming traffic to |
| 422 | update its tables) for the traditional method. If the |
| 423 | gratuitous ARP is lost, communication may be |
| 424 | disrupted. |
| 425 | |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 426 | When this policy is used in conjunction with the mii |
Jay Vosburgh | 3915c1e8 | 2008-05-17 21:10:14 -0700 | [diff] [blame] | 427 | monitor, devices which assert link up prior to being |
| 428 | able to actually transmit and receive are particularly |
Matt LaPlante | 19f5946 | 2009-04-27 15:06:31 +0200 | [diff] [blame] | 429 | susceptible to loss of the gratuitous ARP, and an |
Jay Vosburgh | 3915c1e8 | 2008-05-17 21:10:14 -0700 | [diff] [blame] | 430 | appropriate updelay setting may be required. |
| 431 | |
| 432 | follow or 2 |
| 433 | |
| 434 | The "follow" fail_over_mac policy causes the MAC |
| 435 | address of the bond to be selected normally (normally |
| 436 | the MAC address of the first slave added to the bond). |
| 437 | However, the second and subsequent slaves are not set |
| 438 | to this MAC address while they are in a backup role; a |
| 439 | slave is programmed with the bond's MAC address at |
| 440 | failover time (and the formerly active slave receives |
| 441 | the newly active slave's MAC address). |
| 442 | |
| 443 | This policy is useful for multiport devices that |
| 444 | either become confused or incur a performance penalty |
| 445 | when multiple ports are programmed with the same MAC |
| 446 | address. |
| 447 | |
| 448 | |
| 449 | The default policy is none, unless the first slave cannot |
| 450 | change its MAC address, in which case the active policy is |
| 451 | selected by default. |
| 452 | |
| 453 | This option may be modified via sysfs only when no slaves are |
| 454 | present in the bond. |
| 455 | |
| 456 | This option was added in bonding version 3.2.0. The "follow" |
| 457 | policy was added in bonding version 3.3.0. |
Jay Vosburgh | dd957c5 | 2007-10-09 19:57:24 -0700 | [diff] [blame] | 458 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | lacp_rate |
| 460 | |
| 461 | Option specifying the rate in which we'll ask our link partner |
| 462 | to transmit LACPDU packets in 802.3ad mode. Possible values |
| 463 | are: |
| 464 | |
| 465 | slow or 0 |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 466 | Request partner to transmit LACPDUs every 30 seconds |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | |
| 468 | fast or 1 |
| 469 | Request partner to transmit LACPDUs every 1 second |
| 470 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 471 | The default is slow. |
| 472 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | max_bonds |
| 474 | |
| 475 | Specifies the number of bonding devices to create for this |
| 476 | instance of the bonding driver. E.g., if max_bonds is 3, and |
| 477 | the bonding driver is not already loaded, then bond0, bond1 |
Jay Vosburgh | b8a9787 | 2008-06-13 18:12:04 -0700 | [diff] [blame] | 478 | and bond2 will be created. The default value is 1. Specifying |
| 479 | a value of 0 will load bonding, but will not create any devices. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 480 | |
| 481 | miimon |
| 482 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 483 | Specifies the MII link monitoring frequency in milliseconds. |
| 484 | This determines how often the link state of each slave is |
| 485 | inspected for link failures. A value of zero disables MII |
| 486 | link monitoring. A value of 100 is a good starting point. |
| 487 | The use_carrier option, below, affects how the link state is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | determined. See the High Availability section for additional |
| 489 | information. The default value is 0. |
| 490 | |
Nicolas de Pesloüan | 025890b | 2011-08-06 07:06:39 +0000 | [diff] [blame] | 491 | min_links |
| 492 | |
| 493 | Specifies the minimum number of links that must be active before |
| 494 | asserting carrier. It is similar to the Cisco EtherChannel min-links |
| 495 | feature. This allows setting the minimum number of member ports that |
| 496 | must be up (link-up state) before marking the bond device as up |
| 497 | (carrier on). This is useful for situations where higher level services |
| 498 | such as clustering want to ensure a minimum number of low bandwidth |
| 499 | links are active before switchover. This option only affect 802.3ad |
| 500 | mode. |
| 501 | |
| 502 | The default value is 0. This will cause carrier to be asserted (for |
| 503 | 802.3ad mode) whenever there is an active aggregator, regardless of the |
| 504 | number of available links in that aggregator. Note that, because an |
| 505 | aggregator cannot be active without at least one available link, |
| 506 | setting this option to 0 or to 1 has the exact same effect. |
| 507 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | mode |
| 509 | |
| 510 | Specifies one of the bonding policies. The default is |
| 511 | balance-rr (round robin). Possible values are: |
| 512 | |
| 513 | balance-rr or 0 |
| 514 | |
| 515 | Round-robin policy: Transmit packets in sequential |
| 516 | order from the first available slave through the |
| 517 | last. This mode provides load balancing and fault |
| 518 | tolerance. |
| 519 | |
| 520 | active-backup or 1 |
| 521 | |
| 522 | Active-backup policy: Only one slave in the bond is |
| 523 | active. A different slave becomes active if, and only |
| 524 | if, the active slave fails. The bond's MAC address is |
| 525 | externally visible on only one port (network adapter) |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 526 | to avoid confusing the switch. |
| 527 | |
| 528 | In bonding version 2.6.2 or later, when a failover |
| 529 | occurs in active-backup mode, bonding will issue one |
| 530 | or more gratuitous ARPs on the newly active slave. |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 531 | One gratuitous ARP is issued for the bonding master |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 532 | interface and each VLAN interfaces configured above |
| 533 | it, provided that the interface has at least one IP |
| 534 | address configured. Gratuitous ARPs issued for VLAN |
| 535 | interfaces are tagged with the appropriate VLAN id. |
| 536 | |
| 537 | This mode provides fault tolerance. The primary |
| 538 | option, documented below, affects the behavior of this |
| 539 | mode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 540 | |
| 541 | balance-xor or 2 |
| 542 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 543 | XOR policy: Transmit based on the selected transmit |
| 544 | hash policy. The default policy is a simple [(source |
Jianhua Xie | 92abf75 | 2014-07-17 14:16:26 +0800 | [diff] [blame] | 545 | MAC address XOR'd with destination MAC address XOR |
| 546 | packet type ID) modulo slave count]. Alternate transmit |
| 547 | policies may be selected via the xmit_hash_policy option, |
| 548 | described below. |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 549 | |
| 550 | This mode provides load balancing and fault tolerance. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | |
| 552 | broadcast or 3 |
| 553 | |
| 554 | Broadcast policy: transmits everything on all slave |
| 555 | interfaces. This mode provides fault tolerance. |
| 556 | |
| 557 | 802.3ad or 4 |
| 558 | |
| 559 | IEEE 802.3ad Dynamic link aggregation. Creates |
| 560 | aggregation groups that share the same speed and |
| 561 | duplex settings. Utilizes all slaves in the active |
| 562 | aggregator according to the 802.3ad specification. |
| 563 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 564 | Slave selection for outgoing traffic is done according |
| 565 | to the transmit hash policy, which may be changed from |
| 566 | the default simple XOR policy via the xmit_hash_policy |
| 567 | option, documented below. Note that not all transmit |
| 568 | policies may be 802.3ad compliant, particularly in |
| 569 | regards to the packet mis-ordering requirements of |
| 570 | section 43.2.4 of the 802.3ad standard. Differing |
| 571 | peer implementations will have varying tolerances for |
| 572 | noncompliance. |
| 573 | |
| 574 | Prerequisites: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 575 | |
| 576 | 1. Ethtool support in the base drivers for retrieving |
| 577 | the speed and duplex of each slave. |
| 578 | |
| 579 | 2. A switch that supports IEEE 802.3ad Dynamic link |
| 580 | aggregation. |
| 581 | |
| 582 | Most switches will require some type of configuration |
| 583 | to enable 802.3ad mode. |
| 584 | |
| 585 | balance-tlb or 5 |
| 586 | |
| 587 | Adaptive transmit load balancing: channel bonding that |
Mahesh Bandewar | e9f0fb8 | 2014-04-22 16:30:22 -0700 | [diff] [blame] | 588 | does not require any special switch support. |
| 589 | |
| 590 | In tlb_dynamic_lb=1 mode; the outgoing traffic is |
| 591 | distributed according to the current load (computed |
| 592 | relative to the speed) on each slave. |
| 593 | |
| 594 | In tlb_dynamic_lb=0 mode; the load balancing based on |
| 595 | current load is disabled and the load is distributed |
| 596 | only using the hash distribution. |
| 597 | |
| 598 | Incoming traffic is received by the current slave. |
| 599 | If the receiving slave fails, another slave takes over |
| 600 | the MAC address of the failed receiving slave. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | |
| 602 | Prerequisite: |
| 603 | |
| 604 | Ethtool support in the base drivers for retrieving the |
| 605 | speed of each slave. |
| 606 | |
| 607 | balance-alb or 6 |
| 608 | |
| 609 | Adaptive load balancing: includes balance-tlb plus |
| 610 | receive load balancing (rlb) for IPV4 traffic, and |
| 611 | does not require any special switch support. The |
| 612 | receive load balancing is achieved by ARP negotiation. |
| 613 | The bonding driver intercepts the ARP Replies sent by |
| 614 | the local system on their way out and overwrites the |
| 615 | source hardware address with the unique hardware |
| 616 | address of one of the slaves in the bond such that |
| 617 | different peers use different hardware addresses for |
| 618 | the server. |
| 619 | |
| 620 | Receive traffic from connections created by the server |
| 621 | is also balanced. When the local system sends an ARP |
| 622 | Request the bonding driver copies and saves the peer's |
| 623 | IP information from the ARP packet. When the ARP |
| 624 | Reply arrives from the peer, its hardware address is |
| 625 | retrieved and the bonding driver initiates an ARP |
| 626 | reply to this peer assigning it to one of the slaves |
| 627 | in the bond. A problematic outcome of using ARP |
| 628 | negotiation for balancing is that each time that an |
| 629 | ARP request is broadcast it uses the hardware address |
| 630 | of the bond. Hence, peers learn the hardware address |
| 631 | of the bond and the balancing of receive traffic |
| 632 | collapses to the current slave. This is handled by |
| 633 | sending updates (ARP Replies) to all the peers with |
| 634 | their individually assigned hardware address such that |
| 635 | the traffic is redistributed. Receive traffic is also |
| 636 | redistributed when a new slave is added to the bond |
| 637 | and when an inactive slave is re-activated. The |
| 638 | receive load is distributed sequentially (round robin) |
| 639 | among the group of highest speed slaves in the bond. |
| 640 | |
| 641 | When a link is reconnected or a new slave joins the |
| 642 | bond the receive traffic is redistributed among all |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 643 | active slaves in the bond by initiating ARP Replies |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 644 | with the selected MAC address to each of the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | clients. The updelay parameter (detailed below) must |
| 646 | be set to a value equal or greater than the switch's |
| 647 | forwarding delay so that the ARP Replies sent to the |
| 648 | peers will not be blocked by the switch. |
| 649 | |
| 650 | Prerequisites: |
| 651 | |
| 652 | 1. Ethtool support in the base drivers for retrieving |
| 653 | the speed of each slave. |
| 654 | |
| 655 | 2. Base driver support for setting the hardware |
| 656 | address of a device while it is open. This is |
| 657 | required so that there will always be one slave in the |
| 658 | team using the bond hardware address (the |
| 659 | curr_active_slave) while having a unique hardware |
| 660 | address for each slave in the bond. If the |
| 661 | curr_active_slave fails its hardware address is |
| 662 | swapped with the new curr_active_slave that was |
| 663 | chosen. |
| 664 | |
Jay Vosburgh | b59f9f7 | 2008-06-13 18:12:03 -0700 | [diff] [blame] | 665 | num_grat_arp |
Brian Haley | 305d552 | 2008-11-04 17:51:14 -0800 | [diff] [blame] | 666 | num_unsol_na |
| 667 | |
Ben Hutchings | ad246c9 | 2011-04-26 15:25:52 +0000 | [diff] [blame] | 668 | Specify the number of peer notifications (gratuitous ARPs and |
| 669 | unsolicited IPv6 Neighbor Advertisements) to be issued after a |
| 670 | failover event. As soon as the link is up on the new slave |
| 671 | (possibly immediately) a peer notification is sent on the |
| 672 | bonding device and each VLAN sub-device. This is repeated at |
| 673 | each link monitor interval (arp_interval or miimon, whichever |
| 674 | is active) if the number is greater than 1. |
Brian Haley | 305d552 | 2008-11-04 17:51:14 -0800 | [diff] [blame] | 675 | |
Ben Hutchings | ad246c9 | 2011-04-26 15:25:52 +0000 | [diff] [blame] | 676 | The valid range is 0 - 255; the default value is 1. These options |
| 677 | affect only the active-backup mode. These options were added for |
| 678 | bonding versions 3.3.0 and 3.4.0 respectively. |
| 679 | |
Jesper Juhl | 8fb4e13 | 2011-08-01 17:59:44 -0700 | [diff] [blame] | 680 | From Linux 3.0 and bonding version 3.7.1, these notifications |
Ben Hutchings | ad246c9 | 2011-04-26 15:25:52 +0000 | [diff] [blame] | 681 | are generated by the ipv4 and ipv6 code and the numbers of |
| 682 | repetitions cannot be set independently. |
Brian Haley | 305d552 | 2008-11-04 17:51:14 -0800 | [diff] [blame] | 683 | |
Nikolay Aleksandrov | 12465fb | 2013-11-05 13:51:42 +0100 | [diff] [blame] | 684 | packets_per_slave |
| 685 | |
| 686 | Specify the number of packets to transmit through a slave before |
| 687 | moving to the next one. When set to 0 then a slave is chosen at |
| 688 | random. |
| 689 | |
| 690 | The valid range is 0 - 65535; the default value is 1. This option |
| 691 | has effect only in balance-rr mode. |
| 692 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 693 | primary |
| 694 | |
| 695 | A string (eth0, eth2, etc) specifying which slave is the |
| 696 | primary device. The specified device will always be the |
| 697 | active slave while it is available. Only when the primary is |
| 698 | off-line will alternate devices be used. This is useful when |
| 699 | one slave is preferred over another, e.g., when one slave has |
| 700 | higher throughput than another. |
| 701 | |
dingtianhong | e1d206a | 2014-01-18 16:28:57 +0800 | [diff] [blame] | 702 | The primary option is only valid for active-backup(1), |
| 703 | balance-tlb (5) and balance-alb (6) mode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | |
Jiri Pirko | a549952 | 2009-09-25 03:28:09 +0000 | [diff] [blame] | 705 | primary_reselect |
| 706 | |
| 707 | Specifies the reselection policy for the primary slave. This |
| 708 | affects how the primary slave is chosen to become the active slave |
| 709 | when failure of the active slave or recovery of the primary slave |
| 710 | occurs. This option is designed to prevent flip-flopping between |
| 711 | the primary slave and other slaves. Possible values are: |
| 712 | |
| 713 | always or 0 (default) |
| 714 | |
| 715 | The primary slave becomes the active slave whenever it |
| 716 | comes back up. |
| 717 | |
| 718 | better or 1 |
| 719 | |
| 720 | The primary slave becomes the active slave when it comes |
| 721 | back up, if the speed and duplex of the primary slave is |
| 722 | better than the speed and duplex of the current active |
| 723 | slave. |
| 724 | |
| 725 | failure or 2 |
| 726 | |
| 727 | The primary slave becomes the active slave only if the |
| 728 | current active slave fails and the primary slave is up. |
| 729 | |
| 730 | The primary_reselect setting is ignored in two cases: |
| 731 | |
| 732 | If no slaves are active, the first slave to recover is |
| 733 | made the active slave. |
| 734 | |
| 735 | When initially enslaved, the primary slave is always made |
| 736 | the active slave. |
| 737 | |
| 738 | Changing the primary_reselect policy via sysfs will cause an |
| 739 | immediate selection of the best active slave according to the new |
| 740 | policy. This may or may not result in a change of the active |
| 741 | slave, depending upon the circumstances. |
| 742 | |
| 743 | This option was added for bonding version 3.6.0. |
| 744 | |
Mahesh Bandewar | e9f0fb8 | 2014-04-22 16:30:22 -0700 | [diff] [blame] | 745 | tlb_dynamic_lb |
| 746 | |
| 747 | Specifies if dynamic shuffling of flows is enabled in tlb |
| 748 | mode. The value has no effect on any other modes. |
| 749 | |
| 750 | The default behavior of tlb mode is to shuffle active flows across |
| 751 | slaves based on the load in that interval. This gives nice lb |
| 752 | characteristics but can cause packet reordering. If re-ordering is |
| 753 | a concern use this variable to disable flow shuffling and rely on |
| 754 | load balancing provided solely by the hash distribution. |
| 755 | xmit-hash-policy can be used to select the appropriate hashing for |
| 756 | the setup. |
| 757 | |
| 758 | The sysfs entry can be used to change the setting per bond device |
| 759 | and the initial value is derived from the module parameter. The |
| 760 | sysfs entry is allowed to be changed only if the bond device is |
| 761 | down. |
| 762 | |
| 763 | The default value is "1" that enables flow shuffling while value "0" |
| 764 | disables it. This option was added in bonding driver 3.7.1 |
| 765 | |
| 766 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | updelay |
| 768 | |
| 769 | Specifies the time, in milliseconds, to wait before enabling a |
| 770 | slave after a link recovery has been detected. This option is |
| 771 | only valid for the miimon link monitor. The updelay value |
| 772 | should be a multiple of the miimon value; if not, it will be |
| 773 | rounded down to the nearest multiple. The default value is 0. |
| 774 | |
| 775 | use_carrier |
| 776 | |
| 777 | Specifies whether or not miimon should use MII or ETHTOOL |
| 778 | ioctls vs. netif_carrier_ok() to determine the link |
| 779 | status. The MII or ETHTOOL ioctls are less efficient and |
| 780 | utilize a deprecated calling sequence within the kernel. The |
| 781 | netif_carrier_ok() relies on the device driver to maintain its |
| 782 | state with netif_carrier_on/off; at this writing, most, but |
| 783 | not all, device drivers support this facility. |
| 784 | |
| 785 | If bonding insists that the link is up when it should not be, |
| 786 | it may be that your network device driver does not support |
| 787 | netif_carrier_on/off. The default state for netif_carrier is |
| 788 | "carrier on," so if a driver does not support netif_carrier, |
| 789 | it will appear as if the link is always up. In this case, |
| 790 | setting use_carrier to 0 will cause bonding to revert to the |
| 791 | MII / ETHTOOL ioctl method to determine the link state. |
| 792 | |
| 793 | A value of 1 enables the use of netif_carrier_ok(), a value of |
| 794 | 0 will use the deprecated MII / ETHTOOL ioctls. The default |
| 795 | value is 1. |
| 796 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 797 | xmit_hash_policy |
| 798 | |
| 799 | Selects the transmit hash policy to use for slave selection in |
Mahesh Bandewar | f05b42e | 2014-04-22 16:30:20 -0700 | [diff] [blame] | 800 | balance-xor, 802.3ad, and tlb modes. Possible values are: |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 801 | |
| 802 | layer2 |
| 803 | |
Jianhua Xie | 92abf75 | 2014-07-17 14:16:26 +0800 | [diff] [blame] | 804 | Uses XOR of hardware MAC addresses and packet type ID |
| 805 | field to generate the hash. The formula is |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 806 | |
Jianhua Xie | 92abf75 | 2014-07-17 14:16:26 +0800 | [diff] [blame] | 807 | hash = source MAC XOR destination MAC XOR packet type ID |
| 808 | slave number = hash modulo slave count |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 809 | |
| 810 | This algorithm will place all traffic to a particular |
| 811 | network peer on the same slave. |
| 812 | |
| 813 | This algorithm is 802.3ad compliant. |
| 814 | |
Jay Vosburgh | 6f6652b | 2007-12-06 23:40:34 -0800 | [diff] [blame] | 815 | layer2+3 |
| 816 | |
| 817 | This policy uses a combination of layer2 and layer3 |
| 818 | protocol information to generate the hash. |
| 819 | |
| 820 | Uses XOR of hardware MAC addresses and IP addresses to |
Nikolay Aleksandrov | 7a6afab | 2013-10-02 13:39:26 +0200 | [diff] [blame] | 821 | generate the hash. The formula is |
Jay Vosburgh | 6f6652b | 2007-12-06 23:40:34 -0800 | [diff] [blame] | 822 | |
Jianhua Xie | 92abf75 | 2014-07-17 14:16:26 +0800 | [diff] [blame] | 823 | hash = source MAC XOR destination MAC XOR packet type ID |
Nikolay Aleksandrov | 7a6afab | 2013-10-02 13:39:26 +0200 | [diff] [blame] | 824 | hash = hash XOR source IP XOR destination IP |
| 825 | hash = hash XOR (hash RSHIFT 16) |
| 826 | hash = hash XOR (hash RSHIFT 8) |
| 827 | And then hash is reduced modulo slave count. |
Jay Vosburgh | 6f6652b | 2007-12-06 23:40:34 -0800 | [diff] [blame] | 828 | |
Nikolay Aleksandrov | 7a6afab | 2013-10-02 13:39:26 +0200 | [diff] [blame] | 829 | If the protocol is IPv6 then the source and destination |
| 830 | addresses are first hashed using ipv6_addr_hash. |
John Eaglesham | 6b923cb | 2012-08-21 20:43:35 +0000 | [diff] [blame] | 831 | |
Jay Vosburgh | 6f6652b | 2007-12-06 23:40:34 -0800 | [diff] [blame] | 832 | This algorithm will place all traffic to a particular |
| 833 | network peer on the same slave. For non-IP traffic, |
| 834 | the formula is the same as for the layer2 transmit |
| 835 | hash policy. |
| 836 | |
| 837 | This policy is intended to provide a more balanced |
| 838 | distribution of traffic than layer2 alone, especially |
| 839 | in environments where a layer3 gateway device is |
| 840 | required to reach most destinations. |
| 841 | |
Matt LaPlante | d919588 | 2008-07-25 19:45:33 -0700 | [diff] [blame] | 842 | This algorithm is 802.3ad compliant. |
Jay Vosburgh | 6f6652b | 2007-12-06 23:40:34 -0800 | [diff] [blame] | 843 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 844 | layer3+4 |
| 845 | |
| 846 | This policy uses upper layer protocol information, |
| 847 | when available, to generate the hash. This allows for |
| 848 | traffic to a particular network peer to span multiple |
| 849 | slaves, although a single connection will not span |
| 850 | multiple slaves. |
| 851 | |
Nikolay Aleksandrov | 7a6afab | 2013-10-02 13:39:26 +0200 | [diff] [blame] | 852 | The formula for unfragmented TCP and UDP packets is |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 853 | |
Nikolay Aleksandrov | 7a6afab | 2013-10-02 13:39:26 +0200 | [diff] [blame] | 854 | hash = source port, destination port (as in the header) |
| 855 | hash = hash XOR source IP XOR destination IP |
| 856 | hash = hash XOR (hash RSHIFT 16) |
| 857 | hash = hash XOR (hash RSHIFT 8) |
| 858 | And then hash is reduced modulo slave count. |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 859 | |
Nikolay Aleksandrov | 7a6afab | 2013-10-02 13:39:26 +0200 | [diff] [blame] | 860 | If the protocol is IPv6 then the source and destination |
| 861 | addresses are first hashed using ipv6_addr_hash. |
John Eaglesham | 6b923cb | 2012-08-21 20:43:35 +0000 | [diff] [blame] | 862 | |
| 863 | For fragmented TCP or UDP packets and all other IPv4 and |
| 864 | IPv6 protocol traffic, the source and destination port |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 865 | information is omitted. For non-IP traffic, the |
| 866 | formula is the same as for the layer2 transmit hash |
| 867 | policy. |
| 868 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 869 | This algorithm is not fully 802.3ad compliant. A |
| 870 | single TCP or UDP conversation containing both |
| 871 | fragmented and unfragmented packets will see packets |
| 872 | striped across two interfaces. This may result in out |
| 873 | of order delivery. Most traffic types will not meet |
| 874 | this criteria, as TCP rarely fragments traffic, and |
| 875 | most UDP traffic is not involved in extended |
| 876 | conversations. Other implementations of 802.3ad may |
| 877 | or may not tolerate this noncompliance. |
| 878 | |
Nikolay Aleksandrov | 7a6afab | 2013-10-02 13:39:26 +0200 | [diff] [blame] | 879 | encap2+3 |
| 880 | |
| 881 | This policy uses the same formula as layer2+3 but it |
| 882 | relies on skb_flow_dissect to obtain the header fields |
| 883 | which might result in the use of inner headers if an |
| 884 | encapsulation protocol is used. For example this will |
| 885 | improve the performance for tunnel users because the |
| 886 | packets will be distributed according to the encapsulated |
| 887 | flows. |
| 888 | |
| 889 | encap3+4 |
| 890 | |
| 891 | This policy uses the same formula as layer3+4 but it |
| 892 | relies on skb_flow_dissect to obtain the header fields |
| 893 | which might result in the use of inner headers if an |
| 894 | encapsulation protocol is used. For example this will |
| 895 | improve the performance for tunnel users because the |
| 896 | packets will be distributed according to the encapsulated |
| 897 | flows. |
| 898 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 899 | The default value is layer2. This option was added in bonding |
Jay Vosburgh | 6f6652b | 2007-12-06 23:40:34 -0800 | [diff] [blame] | 900 | version 2.6.3. In earlier versions of bonding, this parameter |
| 901 | does not exist, and the layer2 policy is the only policy. The |
| 902 | layer2+3 value was added for bonding version 3.2.2. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 903 | |
Flavio Leitner | c2952c3 | 2010-10-05 14:23:59 +0000 | [diff] [blame] | 904 | resend_igmp |
| 905 | |
| 906 | Specifies the number of IGMP membership reports to be issued after |
| 907 | a failover event. One membership report is issued immediately after |
| 908 | the failover, subsequent packets are sent in each 200ms interval. |
| 909 | |
Flavio Leitner | 94265cf | 2011-05-25 08:38:58 +0000 | [diff] [blame] | 910 | The valid range is 0 - 255; the default value is 1. A value of 0 |
| 911 | prevents the IGMP membership report from being issued in response |
| 912 | to the failover event. |
| 913 | |
| 914 | This option is useful for bonding modes balance-rr (0), active-backup |
| 915 | (1), balance-tlb (5) and balance-alb (6), in which a failover can |
| 916 | switch the IGMP traffic from one slave to another. Therefore a fresh |
| 917 | IGMP report must be issued to cause the switch to forward the incoming |
| 918 | IGMP traffic over the newly selected slave. |
| 919 | |
| 920 | This option was added for bonding version 3.7.0. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 921 | |
dingtianhong | 84a6a0a | 2013-12-21 14:40:22 +0800 | [diff] [blame] | 922 | lp_interval |
| 923 | |
| 924 | Specifies the number of seconds between instances where the bonding |
| 925 | driver sends learning packets to each slaves peer switch. |
| 926 | |
| 927 | The valid range is 1 - 0x7fffffff; the default value is 1. This Option |
| 928 | has effect only in balance-tlb and balance-alb modes. |
| 929 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 930 | 3. Configuring Bonding Devices |
| 931 | ============================== |
| 932 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 933 | You can configure bonding using either your distro's network |
Cong Wang | b1098bb | 2013-05-27 15:49:16 +0000 | [diff] [blame] | 934 | initialization scripts, or manually using either iproute2 or the |
Nicolas de Pesloüan | de221bd | 2011-01-24 13:21:37 +0000 | [diff] [blame] | 935 | sysfs interface. Distros generally use one of three packages for the |
| 936 | network initialization scripts: initscripts, sysconfig or interfaces. |
| 937 | Recent versions of these packages have support for bonding, while older |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 938 | versions do not. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 939 | |
| 940 | We will first describe the options for configuring bonding for |
Nicolas de Pesloüan | de221bd | 2011-01-24 13:21:37 +0000 | [diff] [blame] | 941 | distros using versions of initscripts, sysconfig and interfaces with full |
| 942 | or partial support for bonding, then provide information on enabling |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 943 | bonding without support from the network initialization scripts (i.e., |
| 944 | older versions of initscripts or sysconfig). |
| 945 | |
Nicolas de Pesloüan | de221bd | 2011-01-24 13:21:37 +0000 | [diff] [blame] | 946 | If you're unsure whether your distro uses sysconfig, |
| 947 | initscripts or interfaces, or don't know if it's new enough, have no fear. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 948 | Determining this is fairly straightforward. |
| 949 | |
Nicolas de Pesloüan | de221bd | 2011-01-24 13:21:37 +0000 | [diff] [blame] | 950 | First, look for a file called interfaces in /etc/network directory. |
| 951 | If this file is present in your system, then your system use interfaces. See |
| 952 | Configuration with Interfaces Support. |
| 953 | |
| 954 | Else, issue the command: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 955 | |
| 956 | $ rpm -qf /sbin/ifup |
| 957 | |
| 958 | It will respond with a line of text starting with either |
| 959 | "initscripts" or "sysconfig," followed by some numbers. This is the |
| 960 | package that provides your network initialization scripts. |
| 961 | |
| 962 | Next, to determine if your installation supports bonding, |
| 963 | issue the command: |
| 964 | |
| 965 | $ grep ifenslave /sbin/ifup |
| 966 | |
| 967 | If this returns any matches, then your initscripts or |
| 968 | sysconfig has support for bonding. |
| 969 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 970 | 3.1 Configuration with Sysconfig Support |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 971 | ---------------------------------------- |
| 972 | |
| 973 | This section applies to distros using a version of sysconfig |
| 974 | with bonding support, for example, SuSE Linux Enterprise Server 9. |
| 975 | |
| 976 | SuSE SLES 9's networking configuration system does support |
| 977 | bonding, however, at this writing, the YaST system configuration |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 978 | front end does not provide any means to work with bonding devices. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | Bonding devices can be managed by hand, however, as follows. |
| 980 | |
| 981 | First, if they have not already been configured, configure the |
| 982 | slave devices. On SLES 9, this is most easily done by running the |
| 983 | yast2 sysconfig configuration utility. The goal is for to create an |
| 984 | ifcfg-id file for each slave device. The simplest way to accomplish |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 985 | this is to configure the devices for DHCP (this is only to get the |
| 986 | file ifcfg-id file created; see below for some issues with DHCP). The |
| 987 | name of the configuration file for each device will be of the form: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 988 | |
| 989 | ifcfg-id-xx:xx:xx:xx:xx:xx |
| 990 | |
| 991 | Where the "xx" portion will be replaced with the digits from |
| 992 | the device's permanent MAC address. |
| 993 | |
| 994 | Once the set of ifcfg-id-xx:xx:xx:xx:xx:xx files has been |
| 995 | created, it is necessary to edit the configuration files for the slave |
| 996 | devices (the MAC addresses correspond to those of the slave devices). |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 997 | Before editing, the file will contain multiple lines, and will look |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 998 | something like this: |
| 999 | |
| 1000 | BOOTPROTO='dhcp' |
| 1001 | STARTMODE='on' |
| 1002 | USERCTL='no' |
| 1003 | UNIQUE='XNzu.WeZGOGF+4wE' |
| 1004 | _nm_name='bus-pci-0001:61:01.0' |
| 1005 | |
| 1006 | Change the BOOTPROTO and STARTMODE lines to the following: |
| 1007 | |
| 1008 | BOOTPROTO='none' |
| 1009 | STARTMODE='off' |
| 1010 | |
| 1011 | Do not alter the UNIQUE or _nm_name lines. Remove any other |
| 1012 | lines (USERCTL, etc). |
| 1013 | |
| 1014 | Once the ifcfg-id-xx:xx:xx:xx:xx:xx files have been modified, |
| 1015 | it's time to create the configuration file for the bonding device |
| 1016 | itself. This file is named ifcfg-bondX, where X is the number of the |
| 1017 | bonding device to create, starting at 0. The first such file is |
| 1018 | ifcfg-bond0, the second is ifcfg-bond1, and so on. The sysconfig |
| 1019 | network configuration system will correctly start multiple instances |
| 1020 | of bonding. |
| 1021 | |
| 1022 | The contents of the ifcfg-bondX file is as follows: |
| 1023 | |
| 1024 | BOOTPROTO="static" |
| 1025 | BROADCAST="10.0.2.255" |
| 1026 | IPADDR="10.0.2.10" |
| 1027 | NETMASK="255.255.0.0" |
| 1028 | NETWORK="10.0.2.0" |
| 1029 | REMOTE_IPADDR="" |
| 1030 | STARTMODE="onboot" |
| 1031 | BONDING_MASTER="yes" |
| 1032 | BONDING_MODULE_OPTS="mode=active-backup miimon=100" |
| 1033 | BONDING_SLAVE0="eth0" |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1034 | BONDING_SLAVE1="bus-pci-0000:06:08.1" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1035 | |
| 1036 | Replace the sample BROADCAST, IPADDR, NETMASK and NETWORK |
| 1037 | values with the appropriate values for your network. |
| 1038 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1039 | The STARTMODE specifies when the device is brought online. |
| 1040 | The possible values are: |
| 1041 | |
| 1042 | onboot: The device is started at boot time. If you're not |
| 1043 | sure, this is probably what you want. |
| 1044 | |
| 1045 | manual: The device is started only when ifup is called |
| 1046 | manually. Bonding devices may be configured this |
| 1047 | way if you do not wish them to start automatically |
| 1048 | at boot for some reason. |
| 1049 | |
| 1050 | hotplug: The device is started by a hotplug event. This is not |
| 1051 | a valid choice for a bonding device. |
| 1052 | |
| 1053 | off or ignore: The device configuration is ignored. |
| 1054 | |
| 1055 | The line BONDING_MASTER='yes' indicates that the device is a |
| 1056 | bonding master device. The only useful value is "yes." |
| 1057 | |
| 1058 | The contents of BONDING_MODULE_OPTS are supplied to the |
| 1059 | instance of the bonding module for this device. Specify the options |
| 1060 | for the bonding mode, link monitoring, and so on here. Do not include |
| 1061 | the max_bonds bonding parameter; this will confuse the configuration |
| 1062 | system if you have multiple bonding devices. |
| 1063 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1064 | Finally, supply one BONDING_SLAVEn="slave device" for each |
| 1065 | slave. where "n" is an increasing value, one for each slave. The |
| 1066 | "slave device" is either an interface name, e.g., "eth0", or a device |
| 1067 | specifier for the network device. The interface name is easier to |
| 1068 | find, but the ethN names are subject to change at boot time if, e.g., |
| 1069 | a device early in the sequence has failed. The device specifiers |
| 1070 | (bus-pci-0000:06:08.1 in the example above) specify the physical |
| 1071 | network device, and will not change unless the device's bus location |
| 1072 | changes (for example, it is moved from one PCI slot to another). The |
| 1073 | example above uses one of each type for demonstration purposes; most |
| 1074 | configurations will choose one or the other for all slave devices. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1075 | |
| 1076 | When all configuration files have been modified or created, |
| 1077 | networking must be restarted for the configuration changes to take |
| 1078 | effect. This can be accomplished via the following: |
| 1079 | |
| 1080 | # /etc/init.d/network restart |
| 1081 | |
| 1082 | Note that the network control script (/sbin/ifdown) will |
| 1083 | remove the bonding module as part of the network shutdown processing, |
| 1084 | so it is not necessary to remove the module by hand if, e.g., the |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1085 | module parameters have changed. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1086 | |
| 1087 | Also, at this writing, YaST/YaST2 will not manage bonding |
| 1088 | devices (they do not show bonding interfaces on its list of network |
| 1089 | devices). It is necessary to edit the configuration file by hand to |
| 1090 | change the bonding configuration. |
| 1091 | |
| 1092 | Additional general options and details of the ifcfg file |
| 1093 | format can be found in an example ifcfg template file: |
| 1094 | |
| 1095 | /etc/sysconfig/network/ifcfg.template |
| 1096 | |
| 1097 | Note that the template does not document the various BONDING_ |
| 1098 | settings described above, but does describe many of the other options. |
| 1099 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1100 | 3.1.1 Using DHCP with Sysconfig |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1101 | ------------------------------- |
| 1102 | |
| 1103 | Under sysconfig, configuring a device with BOOTPROTO='dhcp' |
| 1104 | will cause it to query DHCP for its IP address information. At this |
| 1105 | writing, this does not function for bonding devices; the scripts |
| 1106 | attempt to obtain the device address from DHCP prior to adding any of |
| 1107 | the slave devices. Without active slaves, the DHCP requests are not |
| 1108 | sent to the network. |
| 1109 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1110 | 3.1.2 Configuring Multiple Bonds with Sysconfig |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1111 | ----------------------------------------------- |
| 1112 | |
| 1113 | The sysconfig network initialization system is capable of |
| 1114 | handling multiple bonding devices. All that is necessary is for each |
| 1115 | bonding instance to have an appropriately configured ifcfg-bondX file |
| 1116 | (as described above). Do not specify the "max_bonds" parameter to any |
| 1117 | instance of bonding, as this will confuse sysconfig. If you require |
| 1118 | multiple bonding devices with identical parameters, create multiple |
| 1119 | ifcfg-bondX files. |
| 1120 | |
| 1121 | Because the sysconfig scripts supply the bonding module |
| 1122 | options in the ifcfg-bondX file, it is not necessary to add them to |
Lucas De Marchi | 970e248 | 2012-03-30 13:37:16 -0700 | [diff] [blame] | 1123 | the system /etc/modules.d/*.conf configuration files. |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1124 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1125 | 3.2 Configuration with Initscripts Support |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1126 | ------------------------------------------ |
| 1127 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1128 | This section applies to distros using a recent version of |
| 1129 | initscripts with bonding support, for example, Red Hat Enterprise Linux |
| 1130 | version 3 or later, Fedora, etc. On these systems, the network |
| 1131 | initialization scripts have knowledge of bonding, and can be configured to |
| 1132 | control bonding devices. Note that older versions of the initscripts |
| 1133 | package have lower levels of support for bonding; this will be noted where |
| 1134 | applicable. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1135 | |
| 1136 | These distros will not automatically load the network adapter |
| 1137 | driver unless the ethX device is configured with an IP address. |
| 1138 | Because of this constraint, users must manually configure a |
| 1139 | network-script file for all physical adapters that will be members of |
| 1140 | a bondX link. Network script files are located in the directory: |
| 1141 | |
| 1142 | /etc/sysconfig/network-scripts |
| 1143 | |
| 1144 | The file name must be prefixed with "ifcfg-eth" and suffixed |
| 1145 | with the adapter's physical adapter number. For example, the script |
| 1146 | for eth0 would be named /etc/sysconfig/network-scripts/ifcfg-eth0. |
| 1147 | Place the following text in the file: |
| 1148 | |
| 1149 | DEVICE=eth0 |
| 1150 | USERCTL=no |
| 1151 | ONBOOT=yes |
| 1152 | MASTER=bond0 |
| 1153 | SLAVE=yes |
| 1154 | BOOTPROTO=none |
| 1155 | |
| 1156 | The DEVICE= line will be different for every ethX device and |
| 1157 | must correspond with the name of the file, i.e., ifcfg-eth1 must have |
| 1158 | a device line of DEVICE=eth1. The setting of the MASTER= line will |
| 1159 | also depend on the final bonding interface name chosen for your bond. |
| 1160 | As with other network devices, these typically start at 0, and go up |
| 1161 | one for each device, i.e., the first bonding instance is bond0, the |
| 1162 | second is bond1, and so on. |
| 1163 | |
| 1164 | Next, create a bond network script. The file name for this |
| 1165 | script will be /etc/sysconfig/network-scripts/ifcfg-bondX where X is |
| 1166 | the number of the bond. For bond0 the file is named "ifcfg-bond0", |
| 1167 | for bond1 it is named "ifcfg-bond1", and so on. Within that file, |
| 1168 | place the following text: |
| 1169 | |
| 1170 | DEVICE=bond0 |
| 1171 | IPADDR=192.168.1.1 |
| 1172 | NETMASK=255.255.255.0 |
| 1173 | NETWORK=192.168.1.0 |
| 1174 | BROADCAST=192.168.1.255 |
| 1175 | ONBOOT=yes |
| 1176 | BOOTPROTO=none |
| 1177 | USERCTL=no |
| 1178 | |
| 1179 | Be sure to change the networking specific lines (IPADDR, |
| 1180 | NETMASK, NETWORK and BROADCAST) to match your network configuration. |
| 1181 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1182 | For later versions of initscripts, such as that found with Fedora |
Andy Gospodarek | 3f8b4b1 | 2008-10-22 11:19:48 +0000 | [diff] [blame] | 1183 | 7 (or later) and Red Hat Enterprise Linux version 5 (or later), it is possible, |
| 1184 | and, indeed, preferable, to specify the bonding options in the ifcfg-bond0 |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1185 | file, e.g. a line of the format: |
| 1186 | |
Andy Gospodarek | 3f8b4b1 | 2008-10-22 11:19:48 +0000 | [diff] [blame] | 1187 | BONDING_OPTS="mode=active-backup arp_interval=60 arp_ip_target=192.168.1.254" |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1188 | |
| 1189 | will configure the bond with the specified options. The options |
| 1190 | specified in BONDING_OPTS are identical to the bonding module parameters |
Andy Gospodarek | 3f8b4b1 | 2008-10-22 11:19:48 +0000 | [diff] [blame] | 1191 | except for the arp_ip_target field when using versions of initscripts older |
| 1192 | than and 8.57 (Fedora 8) and 8.45.19 (Red Hat Enterprise Linux 5.2). When |
| 1193 | using older versions each target should be included as a separate option and |
| 1194 | should be preceded by a '+' to indicate it should be added to the list of |
| 1195 | queried targets, e.g., |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1196 | |
| 1197 | arp_ip_target=+192.168.1.1 arp_ip_target=+192.168.1.2 |
| 1198 | |
| 1199 | is the proper syntax to specify multiple targets. When specifying |
Lucas De Marchi | 970e248 | 2012-03-30 13:37:16 -0700 | [diff] [blame] | 1200 | options via BONDING_OPTS, it is not necessary to edit /etc/modprobe.d/*.conf. |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1201 | |
Andy Gospodarek | 3f8b4b1 | 2008-10-22 11:19:48 +0000 | [diff] [blame] | 1202 | For even older versions of initscripts that do not support |
Lucas De Marchi | 970e248 | 2012-03-30 13:37:16 -0700 | [diff] [blame] | 1203 | BONDING_OPTS, it is necessary to edit /etc/modprobe.d/*.conf, depending upon |
| 1204 | your distro) to load the bonding module with your desired options when the |
| 1205 | bond0 interface is brought up. The following lines in /etc/modprobe.d/*.conf |
| 1206 | will load the bonding module, and select its options: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1207 | |
| 1208 | alias bond0 bonding |
| 1209 | options bond0 mode=balance-alb miimon=100 |
| 1210 | |
| 1211 | Replace the sample parameters with the appropriate set of |
| 1212 | options for your configuration. |
| 1213 | |
| 1214 | Finally run "/etc/rc.d/init.d/network restart" as root. This |
| 1215 | will restart the networking subsystem and your bond link should be now |
| 1216 | up and running. |
| 1217 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1218 | 3.2.1 Using DHCP with Initscripts |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1219 | --------------------------------- |
| 1220 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1221 | Recent versions of initscripts (the versions supplied with Fedora |
| 1222 | Core 3 and Red Hat Enterprise Linux 4, or later versions, are reported to |
| 1223 | work) have support for assigning IP information to bonding devices via |
| 1224 | DHCP. |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1225 | |
| 1226 | To configure bonding for DHCP, configure it as described |
| 1227 | above, except replace the line "BOOTPROTO=none" with "BOOTPROTO=dhcp" |
| 1228 | and add a line consisting of "TYPE=Bonding". Note that the TYPE value |
| 1229 | is case sensitive. |
| 1230 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1231 | 3.2.2 Configuring Multiple Bonds with Initscripts |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1232 | ------------------------------------------------- |
| 1233 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1234 | Initscripts packages that are included with Fedora 7 and Red Hat |
| 1235 | Enterprise Linux 5 support multiple bonding interfaces by simply |
| 1236 | specifying the appropriate BONDING_OPTS= in ifcfg-bondX where X is the |
| 1237 | number of the bond. This support requires sysfs support in the kernel, |
| 1238 | and a bonding driver of version 3.0.0 or later. Other configurations may |
| 1239 | not support this method for specifying multiple bonding interfaces; for |
| 1240 | those instances, see the "Configuring Multiple Bonds Manually" section, |
| 1241 | below. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1242 | |
Cong Wang | b1098bb | 2013-05-27 15:49:16 +0000 | [diff] [blame] | 1243 | 3.3 Configuring Bonding Manually with iproute2 |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1244 | ----------------------------------------------- |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1245 | |
| 1246 | This section applies to distros whose network initialization |
| 1247 | scripts (the sysconfig or initscripts package) do not have specific |
| 1248 | knowledge of bonding. One such distro is SuSE Linux Enterprise Server |
| 1249 | version 8. |
| 1250 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1251 | The general method for these systems is to place the bonding |
Lucas De Marchi | 970e248 | 2012-03-30 13:37:16 -0700 | [diff] [blame] | 1252 | module parameters into a config file in /etc/modprobe.d/ (as |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1253 | appropriate for the installed distro), then add modprobe and/or |
Cong Wang | b1098bb | 2013-05-27 15:49:16 +0000 | [diff] [blame] | 1254 | `ip link` commands to the system's global init script. The name of |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1255 | the global init script differs; for sysconfig, it is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1256 | /etc/init.d/boot.local and for initscripts it is /etc/rc.d/rc.local. |
| 1257 | |
| 1258 | For example, if you wanted to make a simple bond of two e100 |
| 1259 | devices (presumed to be eth0 and eth1), and have it persist across |
| 1260 | reboots, edit the appropriate file (/etc/init.d/boot.local or |
| 1261 | /etc/rc.d/rc.local), and add the following: |
| 1262 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1263 | modprobe bonding mode=balance-alb miimon=100 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1264 | modprobe e100 |
| 1265 | ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up |
Cong Wang | b1098bb | 2013-05-27 15:49:16 +0000 | [diff] [blame] | 1266 | ip link set eth0 master bond0 |
| 1267 | ip link set eth1 master bond0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1268 | |
| 1269 | Replace the example bonding module parameters and bond0 |
| 1270 | network configuration (IP address, netmask, etc) with the appropriate |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1271 | values for your configuration. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1272 | |
| 1273 | Unfortunately, this method will not provide support for the |
| 1274 | ifup and ifdown scripts on the bond devices. To reload the bonding |
| 1275 | configuration, it is necessary to run the initialization script, e.g., |
| 1276 | |
| 1277 | # /etc/init.d/boot.local |
| 1278 | |
| 1279 | or |
| 1280 | |
| 1281 | # /etc/rc.d/rc.local |
| 1282 | |
| 1283 | It may be desirable in such a case to create a separate script |
| 1284 | which only initializes the bonding configuration, then call that |
| 1285 | separate script from within boot.local. This allows for bonding to be |
| 1286 | enabled without re-running the entire global init script. |
| 1287 | |
| 1288 | To shut down the bonding devices, it is necessary to first |
| 1289 | mark the bonding device itself as being down, then remove the |
| 1290 | appropriate device driver modules. For our example above, you can do |
| 1291 | the following: |
| 1292 | |
| 1293 | # ifconfig bond0 down |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1294 | # rmmod bonding |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | # rmmod e100 |
| 1296 | |
| 1297 | Again, for convenience, it may be desirable to create a script |
| 1298 | with these commands. |
| 1299 | |
| 1300 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1301 | 3.3.1 Configuring Multiple Bonds Manually |
| 1302 | ----------------------------------------- |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1303 | |
| 1304 | This section contains information on configuring multiple |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1305 | bonding devices with differing options for those systems whose network |
| 1306 | initialization scripts lack support for configuring multiple bonds. |
| 1307 | |
| 1308 | If you require multiple bonding devices, but all with the same |
| 1309 | options, you may wish to use the "max_bonds" module parameter, |
| 1310 | documented above. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1311 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1312 | To create multiple bonding devices with differing options, it is |
Rick Jones | f8b72d3 | 2012-07-20 10:51:37 +0000 | [diff] [blame] | 1313 | preferable to use bonding parameters exported by sysfs, documented in the |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1314 | section below. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1315 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1316 | For versions of bonding without sysfs support, the only means to |
| 1317 | provide multiple instances of bonding with differing options is to load |
| 1318 | the bonding driver multiple times. Note that current versions of the |
| 1319 | sysconfig network initialization scripts handle this automatically; if |
| 1320 | your distro uses these scripts, no special action is needed. See the |
| 1321 | section Configuring Bonding Devices, above, if you're not sure about your |
| 1322 | network initialization scripts. |
| 1323 | |
| 1324 | To load multiple instances of the module, it is necessary to |
| 1325 | specify a different name for each instance (the module loading system |
| 1326 | requires that every loaded module, even multiple instances of the same |
| 1327 | module, have a unique name). This is accomplished by supplying multiple |
Lucas De Marchi | 970e248 | 2012-03-30 13:37:16 -0700 | [diff] [blame] | 1328 | sets of bonding options in /etc/modprobe.d/*.conf, for example: |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1329 | |
| 1330 | alias bond0 bonding |
| 1331 | options bond0 -o bond0 mode=balance-rr miimon=100 |
| 1332 | |
| 1333 | alias bond1 bonding |
| 1334 | options bond1 -o bond1 mode=balance-alb miimon=50 |
| 1335 | |
| 1336 | will load the bonding module two times. The first instance is |
| 1337 | named "bond0" and creates the bond0 device in balance-rr mode with an |
| 1338 | miimon of 100. The second instance is named "bond1" and creates the |
| 1339 | bond1 device in balance-alb mode with an miimon of 50. |
| 1340 | |
| 1341 | In some circumstances (typically with older distributions), |
| 1342 | the above does not work, and the second bonding instance never sees |
| 1343 | its options. In that case, the second options line can be substituted |
| 1344 | as follows: |
| 1345 | |
| 1346 | install bond1 /sbin/modprobe --ignore-install bonding -o bond1 \ |
| 1347 | mode=balance-alb miimon=50 |
| 1348 | |
| 1349 | This may be repeated any number of times, specifying a new and |
| 1350 | unique name in place of bond1 for each subsequent instance. |
| 1351 | |
| 1352 | It has been observed that some Red Hat supplied kernels are unable |
| 1353 | to rename modules at load time (the "-o bond1" part). Attempts to pass |
| 1354 | that option to modprobe will produce an "Operation not permitted" error. |
| 1355 | This has been reported on some Fedora Core kernels, and has been seen on |
| 1356 | RHEL 4 as well. On kernels exhibiting this problem, it will be impossible |
| 1357 | to configure multiple bonds with differing parameters (as they are older |
| 1358 | kernels, and also lack sysfs support). |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1359 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1360 | 3.4 Configuring Bonding Manually via Sysfs |
| 1361 | ------------------------------------------ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1362 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 1363 | Starting with version 3.0.0, Channel Bonding may be configured |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1364 | via the sysfs interface. This interface allows dynamic configuration |
| 1365 | of all bonds in the system without unloading the module. It also |
| 1366 | allows for adding and removing bonds at runtime. Ifenslave is no |
| 1367 | longer required, though it is still supported. |
| 1368 | |
| 1369 | Use of the sysfs interface allows you to use multiple bonds |
| 1370 | with different configurations without having to reload the module. |
| 1371 | It also allows you to use multiple, differently configured bonds when |
| 1372 | bonding is compiled into the kernel. |
| 1373 | |
| 1374 | You must have the sysfs filesystem mounted to configure |
| 1375 | bonding this way. The examples in this document assume that you |
| 1376 | are using the standard mount point for sysfs, e.g. /sys. If your |
| 1377 | sysfs filesystem is mounted elsewhere, you will need to adjust the |
| 1378 | example paths accordingly. |
| 1379 | |
| 1380 | Creating and Destroying Bonds |
| 1381 | ----------------------------- |
| 1382 | To add a new bond foo: |
| 1383 | # echo +foo > /sys/class/net/bonding_masters |
| 1384 | |
| 1385 | To remove an existing bond bar: |
| 1386 | # echo -bar > /sys/class/net/bonding_masters |
| 1387 | |
| 1388 | To show all existing bonds: |
| 1389 | # cat /sys/class/net/bonding_masters |
| 1390 | |
| 1391 | NOTE: due to 4K size limitation of sysfs files, this list may be |
| 1392 | truncated if you have more than a few hundred bonds. This is unlikely |
| 1393 | to occur under normal operating conditions. |
| 1394 | |
| 1395 | Adding and Removing Slaves |
| 1396 | -------------------------- |
| 1397 | Interfaces may be enslaved to a bond using the file |
| 1398 | /sys/class/net/<bond>/bonding/slaves. The semantics for this file |
| 1399 | are the same as for the bonding_masters file. |
| 1400 | |
| 1401 | To enslave interface eth0 to bond bond0: |
| 1402 | # ifconfig bond0 up |
| 1403 | # echo +eth0 > /sys/class/net/bond0/bonding/slaves |
| 1404 | |
| 1405 | To free slave eth0 from bond bond0: |
| 1406 | # echo -eth0 > /sys/class/net/bond0/bonding/slaves |
| 1407 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1408 | When an interface is enslaved to a bond, symlinks between the |
| 1409 | two are created in the sysfs filesystem. In this case, you would get |
| 1410 | /sys/class/net/bond0/slave_eth0 pointing to /sys/class/net/eth0, and |
| 1411 | /sys/class/net/eth0/master pointing to /sys/class/net/bond0. |
| 1412 | |
| 1413 | This means that you can tell quickly whether or not an |
| 1414 | interface is enslaved by looking for the master symlink. Thus: |
| 1415 | # echo -eth0 > /sys/class/net/eth0/master/bonding/slaves |
| 1416 | will free eth0 from whatever bond it is enslaved to, regardless of |
| 1417 | the name of the bond interface. |
| 1418 | |
| 1419 | Changing a Bond's Configuration |
| 1420 | ------------------------------- |
| 1421 | Each bond may be configured individually by manipulating the |
| 1422 | files located in /sys/class/net/<bond name>/bonding |
| 1423 | |
| 1424 | The names of these files correspond directly with the command- |
Paolo Ornati | 670e9f3 | 2006-10-03 22:57:56 +0200 | [diff] [blame] | 1425 | line parameters described elsewhere in this file, and, with the |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1426 | exception of arp_ip_target, they accept the same values. To see the |
| 1427 | current setting, simply cat the appropriate file. |
| 1428 | |
| 1429 | A few examples will be given here; for specific usage |
| 1430 | guidelines for each parameter, see the appropriate section in this |
| 1431 | document. |
| 1432 | |
| 1433 | To configure bond0 for balance-alb mode: |
| 1434 | # ifconfig bond0 down |
| 1435 | # echo 6 > /sys/class/net/bond0/bonding/mode |
| 1436 | - or - |
| 1437 | # echo balance-alb > /sys/class/net/bond0/bonding/mode |
| 1438 | NOTE: The bond interface must be down before the mode can be |
| 1439 | changed. |
| 1440 | |
| 1441 | To enable MII monitoring on bond0 with a 1 second interval: |
| 1442 | # echo 1000 > /sys/class/net/bond0/bonding/miimon |
| 1443 | NOTE: If ARP monitoring is enabled, it will disabled when MII |
| 1444 | monitoring is enabled, and vice-versa. |
| 1445 | |
| 1446 | To add ARP targets: |
| 1447 | # echo +192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target |
| 1448 | # echo +192.168.0.101 > /sys/class/net/bond0/bonding/arp_ip_target |
Brian Haley | 5a31bec | 2009-04-13 00:11:30 -0700 | [diff] [blame] | 1449 | NOTE: up to 16 target addresses may be specified. |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1450 | |
| 1451 | To remove an ARP target: |
| 1452 | # echo -192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target |
| 1453 | |
Neil Horman | 7eacd03 | 2013-09-13 11:05:33 -0400 | [diff] [blame] | 1454 | To configure the interval between learning packet transmits: |
| 1455 | # echo 12 > /sys/class/net/bond0/bonding/lp_interval |
| 1456 | NOTE: the lp_inteval is the number of seconds between instances where |
| 1457 | the bonding driver sends learning packets to each slaves peer switch. The |
| 1458 | default interval is 1 second. |
| 1459 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1460 | Example Configuration |
| 1461 | --------------------- |
| 1462 | We begin with the same example that is shown in section 3.3, |
| 1463 | executed with sysfs, and without using ifenslave. |
| 1464 | |
| 1465 | To make a simple bond of two e100 devices (presumed to be eth0 |
| 1466 | and eth1), and have it persist across reboots, edit the appropriate |
| 1467 | file (/etc/init.d/boot.local or /etc/rc.d/rc.local), and add the |
| 1468 | following: |
| 1469 | |
| 1470 | modprobe bonding |
| 1471 | modprobe e100 |
| 1472 | echo balance-alb > /sys/class/net/bond0/bonding/mode |
| 1473 | ifconfig bond0 192.168.1.1 netmask 255.255.255.0 up |
| 1474 | echo 100 > /sys/class/net/bond0/bonding/miimon |
| 1475 | echo +eth0 > /sys/class/net/bond0/bonding/slaves |
| 1476 | echo +eth1 > /sys/class/net/bond0/bonding/slaves |
| 1477 | |
| 1478 | To add a second bond, with two e1000 interfaces in |
| 1479 | active-backup mode, using ARP monitoring, add the following lines to |
| 1480 | your init script: |
| 1481 | |
| 1482 | modprobe e1000 |
| 1483 | echo +bond1 > /sys/class/net/bonding_masters |
| 1484 | echo active-backup > /sys/class/net/bond1/bonding/mode |
| 1485 | ifconfig bond1 192.168.2.1 netmask 255.255.255.0 up |
| 1486 | echo +192.168.2.100 /sys/class/net/bond1/bonding/arp_ip_target |
| 1487 | echo 2000 > /sys/class/net/bond1/bonding/arp_interval |
| 1488 | echo +eth2 > /sys/class/net/bond1/bonding/slaves |
| 1489 | echo +eth3 > /sys/class/net/bond1/bonding/slaves |
| 1490 | |
Nicolas de Pesloüan | de221bd | 2011-01-24 13:21:37 +0000 | [diff] [blame] | 1491 | 3.5 Configuration with Interfaces Support |
| 1492 | ----------------------------------------- |
| 1493 | |
| 1494 | This section applies to distros which use /etc/network/interfaces file |
| 1495 | to describe network interface configuration, most notably Debian and it's |
| 1496 | derivatives. |
| 1497 | |
| 1498 | The ifup and ifdown commands on Debian don't support bonding out of |
| 1499 | the box. The ifenslave-2.6 package should be installed to provide bonding |
| 1500 | support. Once installed, this package will provide bond-* options to be used |
| 1501 | into /etc/network/interfaces. |
| 1502 | |
| 1503 | Note that ifenslave-2.6 package will load the bonding module and use |
| 1504 | the ifenslave command when appropriate. |
| 1505 | |
| 1506 | Example Configurations |
| 1507 | ---------------------- |
| 1508 | |
| 1509 | In /etc/network/interfaces, the following stanza will configure bond0, in |
| 1510 | active-backup mode, with eth0 and eth1 as slaves. |
| 1511 | |
| 1512 | auto bond0 |
| 1513 | iface bond0 inet dhcp |
| 1514 | bond-slaves eth0 eth1 |
| 1515 | bond-mode active-backup |
| 1516 | bond-miimon 100 |
| 1517 | bond-primary eth0 eth1 |
| 1518 | |
| 1519 | If the above configuration doesn't work, you might have a system using |
| 1520 | upstart for system startup. This is most notably true for recent |
| 1521 | Ubuntu versions. The following stanza in /etc/network/interfaces will |
| 1522 | produce the same result on those systems. |
| 1523 | |
| 1524 | auto bond0 |
| 1525 | iface bond0 inet dhcp |
| 1526 | bond-slaves none |
| 1527 | bond-mode active-backup |
| 1528 | bond-miimon 100 |
| 1529 | |
| 1530 | auto eth0 |
| 1531 | iface eth0 inet manual |
| 1532 | bond-master bond0 |
| 1533 | bond-primary eth0 eth1 |
| 1534 | |
| 1535 | auto eth1 |
| 1536 | iface eth1 inet manual |
| 1537 | bond-master bond0 |
| 1538 | bond-primary eth0 eth1 |
| 1539 | |
| 1540 | For a full list of bond-* supported options in /etc/network/interfaces and some |
| 1541 | more advanced examples tailored to you particular distros, see the files in |
| 1542 | /usr/share/doc/ifenslave-2.6. |
| 1543 | |
| 1544 | 3.6 Overriding Configuration for Special Cases |
Andy Gospodarek | bb1d912 | 2010-06-02 08:40:18 +0000 | [diff] [blame] | 1545 | ---------------------------------------------- |
Nicolas de Pesloüan | de221bd | 2011-01-24 13:21:37 +0000 | [diff] [blame] | 1546 | |
Andy Gospodarek | bb1d912 | 2010-06-02 08:40:18 +0000 | [diff] [blame] | 1547 | When using the bonding driver, the physical port which transmits a frame is |
| 1548 | typically selected by the bonding driver, and is not relevant to the user or |
| 1549 | system administrator. The output port is simply selected using the policies of |
| 1550 | the selected bonding mode. On occasion however, it is helpful to direct certain |
| 1551 | classes of traffic to certain physical interfaces on output to implement |
| 1552 | slightly more complex policies. For example, to reach a web server over a |
| 1553 | bonded interface in which eth0 connects to a private network, while eth1 |
| 1554 | connects via a public network, it may be desirous to bias the bond to send said |
| 1555 | traffic over eth0 first, using eth1 only as a fall back, while all other traffic |
| 1556 | can safely be sent over either interface. Such configurations may be achieved |
| 1557 | using the traffic control utilities inherent in linux. |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1558 | |
Andy Gospodarek | bb1d912 | 2010-06-02 08:40:18 +0000 | [diff] [blame] | 1559 | By default the bonding driver is multiqueue aware and 16 queues are created |
| 1560 | when the driver initializes (see Documentation/networking/multiqueue.txt |
| 1561 | for details). If more or less queues are desired the module parameter |
| 1562 | tx_queues can be used to change this value. There is no sysfs parameter |
| 1563 | available as the allocation is done at module init time. |
| 1564 | |
| 1565 | The output of the file /proc/net/bonding/bondX has changed so the output Queue |
| 1566 | ID is now printed for each slave: |
| 1567 | |
| 1568 | Bonding Mode: fault-tolerance (active-backup) |
| 1569 | Primary Slave: None |
| 1570 | Currently Active Slave: eth0 |
| 1571 | MII Status: up |
| 1572 | MII Polling Interval (ms): 0 |
| 1573 | Up Delay (ms): 0 |
| 1574 | Down Delay (ms): 0 |
| 1575 | |
| 1576 | Slave Interface: eth0 |
| 1577 | MII Status: up |
| 1578 | Link Failure Count: 0 |
| 1579 | Permanent HW addr: 00:1a:a0:12:8f:cb |
| 1580 | Slave queue ID: 0 |
| 1581 | |
| 1582 | Slave Interface: eth1 |
| 1583 | MII Status: up |
| 1584 | Link Failure Count: 0 |
| 1585 | Permanent HW addr: 00:1a:a0:12:8f:cc |
| 1586 | Slave queue ID: 2 |
| 1587 | |
| 1588 | The queue_id for a slave can be set using the command: |
| 1589 | |
| 1590 | # echo "eth1:2" > /sys/class/net/bond0/bonding/queue_id |
| 1591 | |
| 1592 | Any interface that needs a queue_id set should set it with multiple calls |
| 1593 | like the one above until proper priorities are set for all interfaces. On |
| 1594 | distributions that allow configuration via initscripts, multiple 'queue_id' |
| 1595 | arguments can be added to BONDING_OPTS to set all needed slave queues. |
| 1596 | |
| 1597 | These queue id's can be used in conjunction with the tc utility to configure |
| 1598 | a multiqueue qdisc and filters to bias certain traffic to transmit on certain |
| 1599 | slave devices. For instance, say we wanted, in the above configuration to |
| 1600 | force all traffic bound to 192.168.1.100 to use eth1 in the bond as its output |
| 1601 | device. The following commands would accomplish this: |
| 1602 | |
| 1603 | # tc qdisc add dev bond0 handle 1 root multiq |
| 1604 | |
| 1605 | # tc filter add dev bond0 protocol ip parent 1: prio 1 u32 match ip dst \ |
| 1606 | 192.168.1.100 action skbedit queue_mapping 2 |
| 1607 | |
| 1608 | These commands tell the kernel to attach a multiqueue queue discipline to the |
| 1609 | bond0 interface and filter traffic enqueued to it, such that packets with a dst |
| 1610 | ip of 192.168.1.100 have their output queue mapping value overwritten to 2. |
| 1611 | This value is then passed into the driver, causing the normal output path |
| 1612 | selection policy to be overridden, selecting instead qid 2, which maps to eth1. |
| 1613 | |
| 1614 | Note that qid values begin at 1. Qid 0 is reserved to initiate to the driver |
| 1615 | that normal output policy selection should take place. One benefit to simply |
| 1616 | leaving the qid for a slave to 0 is the multiqueue awareness in the bonding |
| 1617 | driver that is now present. This awareness allows tc filters to be placed on |
| 1618 | slave devices as well as bond devices and the bonding driver will simply act as |
| 1619 | a pass-through for selecting output queues on the slave device rather than |
| 1620 | output port selection. |
| 1621 | |
| 1622 | This feature first appeared in bonding driver version 3.7.0 and support for |
| 1623 | output slave selection was limited to round-robin and active-backup modes. |
| 1624 | |
| 1625 | 4 Querying Bonding Configuration |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1626 | ================================= |
| 1627 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1628 | 4.1 Bonding Configuration |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1629 | ------------------------- |
| 1630 | |
| 1631 | Each bonding device has a read-only file residing in the |
| 1632 | /proc/net/bonding directory. The file contents include information |
| 1633 | about the bonding configuration, options and state of each slave. |
| 1634 | |
| 1635 | For example, the contents of /proc/net/bonding/bond0 after the |
| 1636 | driver is loaded with parameters of mode=0 and miimon=1000 is |
| 1637 | generally as follows: |
| 1638 | |
| 1639 | Ethernet Channel Bonding Driver: 2.6.1 (October 29, 2004) |
| 1640 | Bonding Mode: load balancing (round-robin) |
| 1641 | Currently Active Slave: eth0 |
| 1642 | MII Status: up |
| 1643 | MII Polling Interval (ms): 1000 |
| 1644 | Up Delay (ms): 0 |
| 1645 | Down Delay (ms): 0 |
| 1646 | |
| 1647 | Slave Interface: eth1 |
| 1648 | MII Status: up |
| 1649 | Link Failure Count: 1 |
| 1650 | |
| 1651 | Slave Interface: eth0 |
| 1652 | MII Status: up |
| 1653 | Link Failure Count: 1 |
| 1654 | |
| 1655 | The precise format and contents will change depending upon the |
| 1656 | bonding configuration, state, and version of the bonding driver. |
| 1657 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1658 | 4.2 Network configuration |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1659 | ------------------------- |
| 1660 | |
| 1661 | The network configuration can be inspected using the ifconfig |
| 1662 | command. Bonding devices will have the MASTER flag set; Bonding slave |
| 1663 | devices will have the SLAVE flag set. The ifconfig output does not |
| 1664 | contain information on which slaves are associated with which masters. |
| 1665 | |
| 1666 | In the example below, the bond0 interface is the master |
| 1667 | (MASTER) while eth0 and eth1 are slaves (SLAVE). Notice all slaves of |
| 1668 | bond0 have the same MAC address (HWaddr) as bond0 for all modes except |
| 1669 | TLB and ALB that require a unique MAC address for each slave. |
| 1670 | |
| 1671 | # /sbin/ifconfig |
| 1672 | bond0 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 |
| 1673 | inet addr:XXX.XXX.XXX.YYY Bcast:XXX.XXX.XXX.255 Mask:255.255.252.0 |
| 1674 | UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1 |
| 1675 | RX packets:7224794 errors:0 dropped:0 overruns:0 frame:0 |
| 1676 | TX packets:3286647 errors:1 dropped:0 overruns:1 carrier:0 |
| 1677 | collisions:0 txqueuelen:0 |
| 1678 | |
| 1679 | eth0 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1680 | UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1 |
| 1681 | RX packets:3573025 errors:0 dropped:0 overruns:0 frame:0 |
| 1682 | TX packets:1643167 errors:1 dropped:0 overruns:1 carrier:0 |
| 1683 | collisions:0 txqueuelen:100 |
| 1684 | Interrupt:10 Base address:0x1080 |
| 1685 | |
| 1686 | eth1 Link encap:Ethernet HWaddr 00:C0:F0:1F:37:B4 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1687 | UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1 |
| 1688 | RX packets:3651769 errors:0 dropped:0 overruns:0 frame:0 |
| 1689 | TX packets:1643480 errors:0 dropped:0 overruns:0 carrier:0 |
| 1690 | collisions:0 txqueuelen:100 |
| 1691 | Interrupt:9 Base address:0x1400 |
| 1692 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1693 | 5. Switch Configuration |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1694 | ======================= |
| 1695 | |
| 1696 | For this section, "switch" refers to whatever system the |
| 1697 | bonded devices are directly connected to (i.e., where the other end of |
| 1698 | the cable plugs into). This may be an actual dedicated switch device, |
| 1699 | or it may be another regular system (e.g., another computer running |
| 1700 | Linux), |
| 1701 | |
| 1702 | The active-backup, balance-tlb and balance-alb modes do not |
| 1703 | require any specific configuration of the switch. |
| 1704 | |
| 1705 | The 802.3ad mode requires that the switch have the appropriate |
| 1706 | ports configured as an 802.3ad aggregation. The precise method used |
| 1707 | to configure this varies from switch to switch, but, for example, a |
| 1708 | Cisco 3550 series switch requires that the appropriate ports first be |
| 1709 | grouped together in a single etherchannel instance, then that |
| 1710 | etherchannel is set to mode "lacp" to enable 802.3ad (instead of |
| 1711 | standard EtherChannel). |
| 1712 | |
| 1713 | The balance-rr, balance-xor and broadcast modes generally |
| 1714 | require that the switch have the appropriate ports grouped together. |
| 1715 | The nomenclature for such a group differs between switches, it may be |
| 1716 | called an "etherchannel" (as in the Cisco example, above), a "trunk |
| 1717 | group" or some other similar variation. For these modes, each switch |
| 1718 | will also have its own configuration options for the switch's transmit |
| 1719 | policy to the bond. Typical choices include XOR of either the MAC or |
| 1720 | IP addresses. The transmit policy of the two peers does not need to |
| 1721 | match. For these three modes, the bonding mode really selects a |
| 1722 | transmit policy for an EtherChannel group; all three will interoperate |
| 1723 | with another EtherChannel group. |
| 1724 | |
| 1725 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1726 | 6. 802.1q VLAN Support |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1727 | ====================== |
| 1728 | |
| 1729 | It is possible to configure VLAN devices over a bond interface |
| 1730 | using the 8021q driver. However, only packets coming from the 8021q |
| 1731 | driver and passing through bonding will be tagged by default. Self |
| 1732 | generated packets, for example, bonding's learning packets or ARP |
| 1733 | packets generated by either ALB mode or the ARP monitor mechanism, are |
| 1734 | tagged internally by bonding itself. As a result, bonding must |
| 1735 | "learn" the VLAN IDs configured above it, and use those IDs to tag |
| 1736 | self generated packets. |
| 1737 | |
| 1738 | For reasons of simplicity, and to support the use of adapters |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1739 | that can do VLAN hardware acceleration offloading, the bonding |
| 1740 | interface declares itself as fully hardware offloading capable, it gets |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1741 | the add_vid/kill_vid notifications to gather the necessary |
| 1742 | information, and it propagates those actions to the slaves. In case |
| 1743 | of mixed adapter types, hardware accelerated tagged packets that |
| 1744 | should go through an adapter that is not offloading capable are |
| 1745 | "un-accelerated" by the bonding driver so the VLAN tag sits in the |
| 1746 | regular location. |
| 1747 | |
| 1748 | VLAN interfaces *must* be added on top of a bonding interface |
| 1749 | only after enslaving at least one slave. The bonding interface has a |
| 1750 | hardware address of 00:00:00:00:00:00 until the first slave is added. |
| 1751 | If the VLAN interface is created prior to the first enslavement, it |
| 1752 | would pick up the all-zeroes hardware address. Once the first slave |
| 1753 | is attached to the bond, the bond device itself will pick up the |
| 1754 | slave's hardware address, which is then available for the VLAN device. |
| 1755 | |
| 1756 | Also, be aware that a similar problem can occur if all slaves |
| 1757 | are released from a bond that still has one or more VLAN interfaces on |
| 1758 | top of it. When a new slave is added, the bonding interface will |
| 1759 | obtain its hardware address from the first slave, which might not |
| 1760 | match the hardware address of the VLAN interfaces (which was |
| 1761 | ultimately copied from an earlier slave). |
| 1762 | |
| 1763 | There are two methods to insure that the VLAN device operates |
| 1764 | with the correct hardware address if all slaves are removed from a |
| 1765 | bond interface: |
| 1766 | |
| 1767 | 1. Remove all VLAN interfaces then recreate them |
| 1768 | |
| 1769 | 2. Set the bonding interface's hardware address so that it |
| 1770 | matches the hardware address of the VLAN interfaces. |
| 1771 | |
| 1772 | Note that changing a VLAN interface's HW address would set the |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1773 | underlying device -- i.e. the bonding interface -- to promiscuous |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1774 | mode, which might not be what you want. |
| 1775 | |
| 1776 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1777 | 7. Link Monitoring |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1778 | ================== |
| 1779 | |
| 1780 | The bonding driver at present supports two schemes for |
| 1781 | monitoring a slave device's link state: the ARP monitor and the MII |
| 1782 | monitor. |
| 1783 | |
| 1784 | At the present time, due to implementation restrictions in the |
| 1785 | bonding driver itself, it is not possible to enable both ARP and MII |
| 1786 | monitoring simultaneously. |
| 1787 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1788 | 7.1 ARP Monitor Operation |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1789 | ------------------------- |
| 1790 | |
| 1791 | The ARP monitor operates as its name suggests: it sends ARP |
| 1792 | queries to one or more designated peer systems on the network, and |
| 1793 | uses the response as an indication that the link is operating. This |
| 1794 | gives some assurance that traffic is actually flowing to and from one |
| 1795 | or more peers on the local network. |
| 1796 | |
| 1797 | The ARP monitor relies on the device driver itself to verify |
| 1798 | that traffic is flowing. In particular, the driver must keep up to |
| 1799 | date the last receive time, dev->last_rx, and transmit start time, |
| 1800 | dev->trans_start. If these are not updated by the driver, then the |
| 1801 | ARP monitor will immediately fail any slaves using that driver, and |
| 1802 | those slaves will stay down. If networking monitoring (tcpdump, etc) |
| 1803 | shows the ARP requests and replies on the network, then it may be that |
| 1804 | your device driver is not updating last_rx and trans_start. |
| 1805 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1806 | 7.2 Configuring Multiple ARP Targets |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1807 | ------------------------------------ |
| 1808 | |
| 1809 | While ARP monitoring can be done with just one target, it can |
| 1810 | be useful in a High Availability setup to have several targets to |
| 1811 | monitor. In the case of just one target, the target itself may go |
| 1812 | down or have a problem making it unresponsive to ARP requests. Having |
| 1813 | an additional target (or several) increases the reliability of the ARP |
| 1814 | monitoring. |
| 1815 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 1816 | Multiple ARP targets must be separated by commas as follows: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1817 | |
| 1818 | # example options for ARP monitoring with three targets |
| 1819 | alias bond0 bonding |
| 1820 | options bond0 arp_interval=60 arp_ip_target=192.168.0.1,192.168.0.3,192.168.0.9 |
| 1821 | |
| 1822 | For just a single target the options would resemble: |
| 1823 | |
| 1824 | # example options for ARP monitoring with one target |
| 1825 | alias bond0 bonding |
| 1826 | options bond0 arp_interval=60 arp_ip_target=192.168.0.100 |
| 1827 | |
| 1828 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1829 | 7.3 MII Monitor Operation |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1830 | ------------------------- |
| 1831 | |
| 1832 | The MII monitor monitors only the carrier state of the local |
| 1833 | network interface. It accomplishes this in one of three ways: by |
| 1834 | depending upon the device driver to maintain its carrier state, by |
| 1835 | querying the device's MII registers, or by making an ethtool query to |
| 1836 | the device. |
| 1837 | |
| 1838 | If the use_carrier module parameter is 1 (the default value), |
| 1839 | then the MII monitor will rely on the driver for carrier state |
| 1840 | information (via the netif_carrier subsystem). As explained in the |
| 1841 | use_carrier parameter information, above, if the MII monitor fails to |
| 1842 | detect carrier loss on the device (e.g., when the cable is physically |
| 1843 | disconnected), it may be that the driver does not support |
| 1844 | netif_carrier. |
| 1845 | |
| 1846 | If use_carrier is 0, then the MII monitor will first query the |
| 1847 | device's (via ioctl) MII registers and check the link state. If that |
| 1848 | request fails (not just that it returns carrier down), then the MII |
| 1849 | monitor will make an ethtool ETHOOL_GLINK request to attempt to obtain |
| 1850 | the same information. If both methods fail (i.e., the driver either |
| 1851 | does not support or had some error in processing both the MII register |
| 1852 | and ethtool requests), then the MII monitor will assume the link is |
| 1853 | up. |
| 1854 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1855 | 8. Potential Sources of Trouble |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1856 | =============================== |
| 1857 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1858 | 8.1 Adventures in Routing |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1859 | ------------------------- |
| 1860 | |
| 1861 | When bonding is configured, it is important that the slave |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1862 | devices not have routes that supersede routes of the master (or, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1863 | generally, not have routes at all). For example, suppose the bonding |
| 1864 | device bond0 has two slaves, eth0 and eth1, and the routing table is |
| 1865 | as follows: |
| 1866 | |
| 1867 | Kernel IP routing table |
| 1868 | Destination Gateway Genmask Flags MSS Window irtt Iface |
| 1869 | 10.0.0.0 0.0.0.0 255.255.0.0 U 40 0 0 eth0 |
| 1870 | 10.0.0.0 0.0.0.0 255.255.0.0 U 40 0 0 eth1 |
| 1871 | 10.0.0.0 0.0.0.0 255.255.0.0 U 40 0 0 bond0 |
| 1872 | 127.0.0.0 0.0.0.0 255.0.0.0 U 40 0 0 lo |
| 1873 | |
| 1874 | This routing configuration will likely still update the |
| 1875 | receive/transmit times in the driver (needed by the ARP monitor), but |
| 1876 | may bypass the bonding driver (because outgoing traffic to, in this |
| 1877 | case, another host on network 10 would use eth0 or eth1 before bond0). |
| 1878 | |
| 1879 | The ARP monitor (and ARP itself) may become confused by this |
| 1880 | configuration, because ARP requests (generated by the ARP monitor) |
| 1881 | will be sent on one interface (bond0), but the corresponding reply |
| 1882 | will arrive on a different interface (eth0). This reply looks to ARP |
| 1883 | as an unsolicited ARP reply (because ARP matches replies on an |
| 1884 | interface basis), and is discarded. The MII monitor is not affected |
| 1885 | by the state of the routing table. |
| 1886 | |
| 1887 | The solution here is simply to insure that slaves do not have |
| 1888 | routes of their own, and if for some reason they must, those routes do |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1889 | not supersede routes of their master. This should generally be the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1890 | case, but unusual configurations or errant manual or automatic static |
| 1891 | route additions may cause trouble. |
| 1892 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1893 | 8.2 Ethernet Device Renaming |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1894 | ---------------------------- |
| 1895 | |
| 1896 | On systems with network configuration scripts that do not |
| 1897 | associate physical devices directly with network interface names (so |
| 1898 | that the same physical device always has the same "ethX" name), it may |
Lucas De Marchi | 970e248 | 2012-03-30 13:37:16 -0700 | [diff] [blame] | 1899 | be necessary to add some special logic to config files in |
| 1900 | /etc/modprobe.d/. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1901 | |
| 1902 | For example, given a modules.conf containing the following: |
| 1903 | |
| 1904 | alias bond0 bonding |
| 1905 | options bond0 mode=some-mode miimon=50 |
| 1906 | alias eth0 tg3 |
| 1907 | alias eth1 tg3 |
| 1908 | alias eth2 e1000 |
| 1909 | alias eth3 e1000 |
| 1910 | |
| 1911 | If neither eth0 and eth1 are slaves to bond0, then when the |
| 1912 | bond0 interface comes up, the devices may end up reordered. This |
| 1913 | happens because bonding is loaded first, then its slave device's |
| 1914 | drivers are loaded next. Since no other drivers have been loaded, |
| 1915 | when the e1000 driver loads, it will receive eth0 and eth1 for its |
| 1916 | devices, but the bonding configuration tries to enslave eth2 and eth3 |
| 1917 | (which may later be assigned to the tg3 devices). |
| 1918 | |
| 1919 | Adding the following: |
| 1920 | |
| 1921 | add above bonding e1000 tg3 |
| 1922 | |
| 1923 | causes modprobe to load e1000 then tg3, in that order, when |
| 1924 | bonding is loaded. This command is fully documented in the |
| 1925 | modules.conf manual page. |
| 1926 | |
Lucas De Marchi | 970e248 | 2012-03-30 13:37:16 -0700 | [diff] [blame] | 1927 | On systems utilizing modprobe an equivalent problem can occur. |
| 1928 | In this case, the following can be added to config files in |
| 1929 | /etc/modprobe.d/ as: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1930 | |
Lucas De Marchi | 78286cd | 2012-03-30 13:37:20 -0700 | [diff] [blame] | 1931 | softdep bonding pre: tg3 e1000 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1932 | |
Lucas De Marchi | 970e248 | 2012-03-30 13:37:16 -0700 | [diff] [blame] | 1933 | This will load tg3 and e1000 modules before loading the bonding one. |
| 1934 | Full documentation on this can be found in the modprobe.d and modprobe |
| 1935 | manual pages. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1936 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1937 | 8.3. Painfully Slow Or No Failed Link Detection By Miimon |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1938 | --------------------------------------------------------- |
| 1939 | |
| 1940 | By default, bonding enables the use_carrier option, which |
| 1941 | instructs bonding to trust the driver to maintain carrier state. |
| 1942 | |
| 1943 | As discussed in the options section, above, some drivers do |
| 1944 | not support the netif_carrier_on/_off link state tracking system. |
| 1945 | With use_carrier enabled, bonding will always see these links as up, |
| 1946 | regardless of their actual state. |
| 1947 | |
| 1948 | Additionally, other drivers do support netif_carrier, but do |
| 1949 | not maintain it in real time, e.g., only polling the link state at |
| 1950 | some fixed interval. In this case, miimon will detect failures, but |
| 1951 | only after some long period of time has expired. If it appears that |
| 1952 | miimon is very slow in detecting link failures, try specifying |
| 1953 | use_carrier=0 to see if that improves the failure detection time. If |
| 1954 | it does, then it may be that the driver checks the carrier state at a |
| 1955 | fixed interval, but does not cache the MII register values (so the |
| 1956 | use_carrier=0 method of querying the registers directly works). If |
| 1957 | use_carrier=0 does not improve the failover, then the driver may cache |
| 1958 | the registers, or the problem may be elsewhere. |
| 1959 | |
| 1960 | Also, remember that miimon only checks for the device's |
| 1961 | carrier state. It has no way to determine the state of devices on or |
| 1962 | beyond other ports of a switch, or if a switch is refusing to pass |
| 1963 | traffic while still maintaining carrier on. |
| 1964 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 1965 | 9. SNMP agents |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1966 | =============== |
| 1967 | |
| 1968 | If running SNMP agents, the bonding driver should be loaded |
| 1969 | before any network drivers participating in a bond. This requirement |
Tobias Klauser | d533f67 | 2005-09-10 00:26:46 -0700 | [diff] [blame] | 1970 | is due to the interface index (ipAdEntIfIndex) being associated to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1971 | the first interface found with a given IP address. That is, there is |
| 1972 | only one ipAdEntIfIndex for each IP address. For example, if eth0 and |
| 1973 | eth1 are slaves of bond0 and the driver for eth0 is loaded before the |
| 1974 | bonding driver, the interface for the IP address will be associated |
| 1975 | with the eth0 interface. This configuration is shown below, the IP |
| 1976 | address 192.168.1.1 has an interface index of 2 which indexes to eth0 |
| 1977 | in the ifDescr table (ifDescr.2). |
| 1978 | |
| 1979 | interfaces.ifTable.ifEntry.ifDescr.1 = lo |
| 1980 | interfaces.ifTable.ifEntry.ifDescr.2 = eth0 |
| 1981 | interfaces.ifTable.ifEntry.ifDescr.3 = eth1 |
| 1982 | interfaces.ifTable.ifEntry.ifDescr.4 = eth2 |
| 1983 | interfaces.ifTable.ifEntry.ifDescr.5 = eth3 |
| 1984 | interfaces.ifTable.ifEntry.ifDescr.6 = bond0 |
| 1985 | ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.10.10.10.10 = 5 |
| 1986 | ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.192.168.1.1 = 2 |
| 1987 | ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.10.74.20.94 = 4 |
| 1988 | ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.127.0.0.1 = 1 |
| 1989 | |
| 1990 | This problem is avoided by loading the bonding driver before |
| 1991 | any network drivers participating in a bond. Below is an example of |
| 1992 | loading the bonding driver first, the IP address 192.168.1.1 is |
| 1993 | correctly associated with ifDescr.2. |
| 1994 | |
| 1995 | interfaces.ifTable.ifEntry.ifDescr.1 = lo |
| 1996 | interfaces.ifTable.ifEntry.ifDescr.2 = bond0 |
| 1997 | interfaces.ifTable.ifEntry.ifDescr.3 = eth0 |
| 1998 | interfaces.ifTable.ifEntry.ifDescr.4 = eth1 |
| 1999 | interfaces.ifTable.ifEntry.ifDescr.5 = eth2 |
| 2000 | interfaces.ifTable.ifEntry.ifDescr.6 = eth3 |
| 2001 | ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.10.10.10.10 = 6 |
| 2002 | ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.192.168.1.1 = 2 |
| 2003 | ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.10.74.20.94 = 5 |
| 2004 | ip.ipAddrTable.ipAddrEntry.ipAdEntIfIndex.127.0.0.1 = 1 |
| 2005 | |
| 2006 | While some distributions may not report the interface name in |
| 2007 | ifDescr, the association between the IP address and IfIndex remains |
| 2008 | and SNMP functions such as Interface_Scan_Next will report that |
| 2009 | association. |
| 2010 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2011 | 10. Promiscuous mode |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2012 | ==================== |
| 2013 | |
| 2014 | When running network monitoring tools, e.g., tcpdump, it is |
| 2015 | common to enable promiscuous mode on the device, so that all traffic |
| 2016 | is seen (instead of seeing only traffic destined for the local host). |
| 2017 | The bonding driver handles promiscuous mode changes to the bonding |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2018 | master device (e.g., bond0), and propagates the setting to the slave |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2019 | devices. |
| 2020 | |
| 2021 | For the balance-rr, balance-xor, broadcast, and 802.3ad modes, |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2022 | the promiscuous mode setting is propagated to all slaves. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2023 | |
| 2024 | For the active-backup, balance-tlb and balance-alb modes, the |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2025 | promiscuous mode setting is propagated only to the active slave. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2026 | |
| 2027 | For balance-tlb mode, the active slave is the slave currently |
| 2028 | receiving inbound traffic. |
| 2029 | |
| 2030 | For balance-alb mode, the active slave is the slave used as a |
| 2031 | "primary." This slave is used for mode-specific control traffic, for |
| 2032 | sending to peers that are unassigned or if the load is unbalanced. |
| 2033 | |
| 2034 | For the active-backup, balance-tlb and balance-alb modes, when |
| 2035 | the active slave changes (e.g., due to a link failure), the |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2036 | promiscuous setting will be propagated to the new active slave. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2037 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2038 | 11. Configuring Bonding for High Availability |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2039 | ============================================= |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2040 | |
| 2041 | High Availability refers to configurations that provide |
| 2042 | maximum network availability by having redundant or backup devices, |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2043 | links or switches between the host and the rest of the world. The |
| 2044 | goal is to provide the maximum availability of network connectivity |
| 2045 | (i.e., the network always works), even though other configurations |
| 2046 | could provide higher throughput. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2047 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2048 | 11.1 High Availability in a Single Switch Topology |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2049 | -------------------------------------------------- |
| 2050 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2051 | If two hosts (or a host and a single switch) are directly |
| 2052 | connected via multiple physical links, then there is no availability |
| 2053 | penalty to optimizing for maximum bandwidth. In this case, there is |
| 2054 | only one switch (or peer), so if it fails, there is no alternative |
| 2055 | access to fail over to. Additionally, the bonding load balance modes |
| 2056 | support link monitoring of their members, so if individual links fail, |
| 2057 | the load will be rebalanced across the remaining devices. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2058 | |
Rick Jones | f8b72d3 | 2012-07-20 10:51:37 +0000 | [diff] [blame] | 2059 | See Section 12, "Configuring Bonding for Maximum Throughput" |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2060 | for information on configuring bonding with one peer device. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2061 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2062 | 11.2 High Availability in a Multiple Switch Topology |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2063 | ---------------------------------------------------- |
| 2064 | |
| 2065 | With multiple switches, the configuration of bonding and the |
| 2066 | network changes dramatically. In multiple switch topologies, there is |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2067 | a trade off between network availability and usable bandwidth. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2068 | |
| 2069 | Below is a sample network, configured to maximize the |
| 2070 | availability of the network: |
| 2071 | |
| 2072 | | | |
| 2073 | |port3 port3| |
| 2074 | +-----+----+ +-----+----+ |
| 2075 | | |port2 ISL port2| | |
| 2076 | | switch A +--------------------------+ switch B | |
| 2077 | | | | | |
| 2078 | +-----+----+ +-----++---+ |
| 2079 | |port1 port1| |
| 2080 | | +-------+ | |
| 2081 | +-------------+ host1 +---------------+ |
| 2082 | eth0 +-------+ eth1 |
| 2083 | |
| 2084 | In this configuration, there is a link between the two |
| 2085 | switches (ISL, or inter switch link), and multiple ports connecting to |
| 2086 | the outside world ("port3" on each switch). There is no technical |
| 2087 | reason that this could not be extended to a third switch. |
| 2088 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2089 | 11.2.1 HA Bonding Mode Selection for Multiple Switch Topology |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2090 | ------------------------------------------------------------- |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2091 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2092 | In a topology such as the example above, the active-backup and |
| 2093 | broadcast modes are the only useful bonding modes when optimizing for |
| 2094 | availability; the other modes require all links to terminate on the |
| 2095 | same peer for them to behave rationally. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2096 | |
| 2097 | active-backup: This is generally the preferred mode, particularly if |
| 2098 | the switches have an ISL and play together well. If the |
| 2099 | network configuration is such that one switch is specifically |
| 2100 | a backup switch (e.g., has lower capacity, higher cost, etc), |
| 2101 | then the primary option can be used to insure that the |
| 2102 | preferred link is always used when it is available. |
| 2103 | |
| 2104 | broadcast: This mode is really a special purpose mode, and is suitable |
| 2105 | only for very specific needs. For example, if the two |
| 2106 | switches are not connected (no ISL), and the networks beyond |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2107 | them are totally independent. In this case, if it is |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2108 | necessary for some specific one-way traffic to reach both |
| 2109 | independent networks, then the broadcast mode may be suitable. |
| 2110 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2111 | 11.2.2 HA Link Monitoring Selection for Multiple Switch Topology |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2112 | ---------------------------------------------------------------- |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2113 | |
| 2114 | The choice of link monitoring ultimately depends upon your |
| 2115 | switch. If the switch can reliably fail ports in response to other |
| 2116 | failures, then either the MII or ARP monitors should work. For |
| 2117 | example, in the above example, if the "port3" link fails at the remote |
| 2118 | end, the MII monitor has no direct means to detect this. The ARP |
| 2119 | monitor could be configured with a target at the remote end of port3, |
| 2120 | thus detecting that failure without switch support. |
| 2121 | |
| 2122 | In general, however, in a multiple switch topology, the ARP |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2123 | monitor can provide a higher level of reliability in detecting end to |
| 2124 | end connectivity failures (which may be caused by the failure of any |
| 2125 | individual component to pass traffic for any reason). Additionally, |
| 2126 | the ARP monitor should be configured with multiple targets (at least |
| 2127 | one for each switch in the network). This will insure that, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2128 | regardless of which switch is active, the ARP monitor has a suitable |
| 2129 | target to query. |
| 2130 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 2131 | Note, also, that of late many switches now support a functionality |
| 2132 | generally referred to as "trunk failover." This is a feature of the |
| 2133 | switch that causes the link state of a particular switch port to be set |
| 2134 | down (or up) when the state of another switch port goes down (or up). |
Matt LaPlante | 19f5946 | 2009-04-27 15:06:31 +0200 | [diff] [blame] | 2135 | Its purpose is to propagate link failures from logically "exterior" ports |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 2136 | to the logically "interior" ports that bonding is able to monitor via |
| 2137 | miimon. Availability and configuration for trunk failover varies by |
| 2138 | switch, but this can be a viable alternative to the ARP monitor when using |
| 2139 | suitable switches. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2140 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2141 | 12. Configuring Bonding for Maximum Throughput |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2142 | ============================================== |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2143 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2144 | 12.1 Maximizing Throughput in a Single Switch Topology |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2145 | ------------------------------------------------------ |
| 2146 | |
| 2147 | In a single switch configuration, the best method to maximize |
| 2148 | throughput depends upon the application and network environment. The |
| 2149 | various load balancing modes each have strengths and weaknesses in |
| 2150 | different environments, as detailed below. |
| 2151 | |
| 2152 | For this discussion, we will break down the topologies into |
| 2153 | two categories. Depending upon the destination of most traffic, we |
| 2154 | categorize them into either "gatewayed" or "local" configurations. |
| 2155 | |
| 2156 | In a gatewayed configuration, the "switch" is acting primarily |
| 2157 | as a router, and the majority of traffic passes through this router to |
| 2158 | other networks. An example would be the following: |
| 2159 | |
| 2160 | |
| 2161 | +----------+ +----------+ |
| 2162 | | |eth0 port1| | to other networks |
| 2163 | | Host A +---------------------+ router +-------------------> |
| 2164 | | +---------------------+ | Hosts B and C are out |
| 2165 | | |eth1 port2| | here somewhere |
| 2166 | +----------+ +----------+ |
| 2167 | |
| 2168 | The router may be a dedicated router device, or another host |
| 2169 | acting as a gateway. For our discussion, the important point is that |
| 2170 | the majority of traffic from Host A will pass through the router to |
| 2171 | some other network before reaching its final destination. |
| 2172 | |
| 2173 | In a gatewayed network configuration, although Host A may |
| 2174 | communicate with many other systems, all of its traffic will be sent |
| 2175 | and received via one other peer on the local network, the router. |
| 2176 | |
| 2177 | Note that the case of two systems connected directly via |
| 2178 | multiple physical links is, for purposes of configuring bonding, the |
| 2179 | same as a gatewayed configuration. In that case, it happens that all |
| 2180 | traffic is destined for the "gateway" itself, not some other network |
| 2181 | beyond the gateway. |
| 2182 | |
| 2183 | In a local configuration, the "switch" is acting primarily as |
| 2184 | a switch, and the majority of traffic passes through this switch to |
| 2185 | reach other stations on the same network. An example would be the |
| 2186 | following: |
| 2187 | |
| 2188 | +----------+ +----------+ +--------+ |
| 2189 | | |eth0 port1| +-------+ Host B | |
| 2190 | | Host A +------------+ switch |port3 +--------+ |
| 2191 | | +------------+ | +--------+ |
| 2192 | | |eth1 port2| +------------------+ Host C | |
| 2193 | +----------+ +----------+port4 +--------+ |
| 2194 | |
| 2195 | |
| 2196 | Again, the switch may be a dedicated switch device, or another |
| 2197 | host acting as a gateway. For our discussion, the important point is |
| 2198 | that the majority of traffic from Host A is destined for other hosts |
| 2199 | on the same local network (Hosts B and C in the above example). |
| 2200 | |
| 2201 | In summary, in a gatewayed configuration, traffic to and from |
| 2202 | the bonded device will be to the same MAC level peer on the network |
| 2203 | (the gateway itself, i.e., the router), regardless of its final |
| 2204 | destination. In a local configuration, traffic flows directly to and |
| 2205 | from the final destinations, thus, each destination (Host B, Host C) |
| 2206 | will be addressed directly by their individual MAC addresses. |
| 2207 | |
| 2208 | This distinction between a gatewayed and a local network |
| 2209 | configuration is important because many of the load balancing modes |
| 2210 | available use the MAC addresses of the local network source and |
| 2211 | destination to make load balancing decisions. The behavior of each |
| 2212 | mode is described below. |
| 2213 | |
| 2214 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2215 | 12.1.1 MT Bonding Mode Selection for Single Switch Topology |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2216 | ----------------------------------------------------------- |
| 2217 | |
| 2218 | This configuration is the easiest to set up and to understand, |
| 2219 | although you will have to decide which bonding mode best suits your |
| 2220 | needs. The trade offs for each mode are detailed below: |
| 2221 | |
| 2222 | balance-rr: This mode is the only mode that will permit a single |
| 2223 | TCP/IP connection to stripe traffic across multiple |
| 2224 | interfaces. It is therefore the only mode that will allow a |
| 2225 | single TCP/IP stream to utilize more than one interface's |
| 2226 | worth of throughput. This comes at a cost, however: the |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 2227 | striping generally results in peer systems receiving packets out |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2228 | of order, causing TCP/IP's congestion control system to kick |
| 2229 | in, often by retransmitting segments. |
| 2230 | |
| 2231 | It is possible to adjust TCP/IP's congestion limits by |
| 2232 | altering the net.ipv4.tcp_reordering sysctl parameter. The |
| 2233 | usual default value is 3, and the maximum useful value is 127. |
| 2234 | For a four interface balance-rr bond, expect that a single |
| 2235 | TCP/IP stream will utilize no more than approximately 2.3 |
| 2236 | interface's worth of throughput, even after adjusting |
| 2237 | tcp_reordering. |
| 2238 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 2239 | Note that the fraction of packets that will be delivered out of |
| 2240 | order is highly variable, and is unlikely to be zero. The level |
| 2241 | of reordering depends upon a variety of factors, including the |
| 2242 | networking interfaces, the switch, and the topology of the |
| 2243 | configuration. Speaking in general terms, higher speed network |
| 2244 | cards produce more reordering (due to factors such as packet |
| 2245 | coalescing), and a "many to many" topology will reorder at a |
| 2246 | higher rate than a "many slow to one fast" configuration. |
| 2247 | |
| 2248 | Many switches do not support any modes that stripe traffic |
| 2249 | (instead choosing a port based upon IP or MAC level addresses); |
| 2250 | for those devices, traffic for a particular connection flowing |
| 2251 | through the switch to a balance-rr bond will not utilize greater |
| 2252 | than one interface's worth of bandwidth. |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2253 | |
| 2254 | If you are utilizing protocols other than TCP/IP, UDP for |
| 2255 | example, and your application can tolerate out of order |
| 2256 | delivery, then this mode can allow for single stream datagram |
| 2257 | performance that scales near linearly as interfaces are added |
| 2258 | to the bond. |
| 2259 | |
| 2260 | This mode requires the switch to have the appropriate ports |
| 2261 | configured for "etherchannel" or "trunking." |
| 2262 | |
| 2263 | active-backup: There is not much advantage in this network topology to |
| 2264 | the active-backup mode, as the inactive backup devices are all |
| 2265 | connected to the same peer as the primary. In this case, a |
| 2266 | load balancing mode (with link monitoring) will provide the |
| 2267 | same level of network availability, but with increased |
| 2268 | available bandwidth. On the plus side, active-backup mode |
| 2269 | does not require any configuration of the switch, so it may |
| 2270 | have value if the hardware available does not support any of |
| 2271 | the load balance modes. |
| 2272 | |
| 2273 | balance-xor: This mode will limit traffic such that packets destined |
| 2274 | for specific peers will always be sent over the same |
| 2275 | interface. Since the destination is determined by the MAC |
| 2276 | addresses involved, this mode works best in a "local" network |
| 2277 | configuration (as described above), with destinations all on |
| 2278 | the same local network. This mode is likely to be suboptimal |
| 2279 | if all your traffic is passed through a single router (i.e., a |
| 2280 | "gatewayed" network configuration, as described above). |
| 2281 | |
| 2282 | As with balance-rr, the switch ports need to be configured for |
| 2283 | "etherchannel" or "trunking." |
| 2284 | |
| 2285 | broadcast: Like active-backup, there is not much advantage to this |
| 2286 | mode in this type of network topology. |
| 2287 | |
| 2288 | 802.3ad: This mode can be a good choice for this type of network |
| 2289 | topology. The 802.3ad mode is an IEEE standard, so all peers |
| 2290 | that implement 802.3ad should interoperate well. The 802.3ad |
| 2291 | protocol includes automatic configuration of the aggregates, |
| 2292 | so minimal manual configuration of the switch is needed |
| 2293 | (typically only to designate that some set of devices is |
| 2294 | available for 802.3ad). The 802.3ad standard also mandates |
| 2295 | that frames be delivered in order (within certain limits), so |
| 2296 | in general single connections will not see misordering of |
| 2297 | packets. The 802.3ad mode does have some drawbacks: the |
| 2298 | standard mandates that all devices in the aggregate operate at |
| 2299 | the same speed and duplex. Also, as with all bonding load |
| 2300 | balance modes other than balance-rr, no single connection will |
| 2301 | be able to utilize more than a single interface's worth of |
| 2302 | bandwidth. |
| 2303 | |
| 2304 | Additionally, the linux bonding 802.3ad implementation |
Jianhua Xie | 92abf75 | 2014-07-17 14:16:26 +0800 | [diff] [blame] | 2305 | distributes traffic by peer (using an XOR of MAC addresses |
| 2306 | and packet type ID), so in a "gatewayed" configuration, all |
| 2307 | outgoing traffic will generally use the same device. Incoming |
| 2308 | traffic may also end up on a single device, but that is |
| 2309 | dependent upon the balancing policy of the peer's 8023.ad |
| 2310 | implementation. In a "local" configuration, traffic will be |
| 2311 | distributed across the devices in the bond. |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2312 | |
| 2313 | Finally, the 802.3ad mode mandates the use of the MII monitor, |
| 2314 | therefore, the ARP monitor is not available in this mode. |
| 2315 | |
| 2316 | balance-tlb: The balance-tlb mode balances outgoing traffic by peer. |
| 2317 | Since the balancing is done according to MAC address, in a |
| 2318 | "gatewayed" configuration (as described above), this mode will |
| 2319 | send all traffic across a single device. However, in a |
| 2320 | "local" network configuration, this mode balances multiple |
| 2321 | local network peers across devices in a vaguely intelligent |
| 2322 | manner (not a simple XOR as in balance-xor or 802.3ad mode), |
| 2323 | so that mathematically unlucky MAC addresses (i.e., ones that |
| 2324 | XOR to the same value) will not all "bunch up" on a single |
| 2325 | interface. |
| 2326 | |
| 2327 | Unlike 802.3ad, interfaces may be of differing speeds, and no |
| 2328 | special switch configuration is required. On the down side, |
| 2329 | in this mode all incoming traffic arrives over a single |
| 2330 | interface, this mode requires certain ethtool support in the |
| 2331 | network device driver of the slave interfaces, and the ARP |
| 2332 | monitor is not available. |
| 2333 | |
| 2334 | balance-alb: This mode is everything that balance-tlb is, and more. |
| 2335 | It has all of the features (and restrictions) of balance-tlb, |
| 2336 | and will also balance incoming traffic from local network |
| 2337 | peers (as described in the Bonding Module Options section, |
| 2338 | above). |
| 2339 | |
| 2340 | The only additional down side to this mode is that the network |
| 2341 | device driver must support changing the hardware address while |
| 2342 | the device is open. |
| 2343 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2344 | 12.1.2 MT Link Monitoring for Single Switch Topology |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2345 | ---------------------------------------------------- |
| 2346 | |
| 2347 | The choice of link monitoring may largely depend upon which |
| 2348 | mode you choose to use. The more advanced load balancing modes do not |
| 2349 | support the use of the ARP monitor, and are thus restricted to using |
| 2350 | the MII monitor (which does not provide as high a level of end to end |
| 2351 | assurance as the ARP monitor). |
| 2352 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2353 | 12.2 Maximum Throughput in a Multiple Switch Topology |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2354 | ----------------------------------------------------- |
| 2355 | |
| 2356 | Multiple switches may be utilized to optimize for throughput |
| 2357 | when they are configured in parallel as part of an isolated network |
| 2358 | between two or more systems, for example: |
| 2359 | |
| 2360 | +-----------+ |
| 2361 | | Host A | |
| 2362 | +-+---+---+-+ |
| 2363 | | | | |
| 2364 | +--------+ | +---------+ |
| 2365 | | | | |
| 2366 | +------+---+ +-----+----+ +-----+----+ |
| 2367 | | Switch A | | Switch B | | Switch C | |
| 2368 | +------+---+ +-----+----+ +-----+----+ |
| 2369 | | | | |
| 2370 | +--------+ | +---------+ |
| 2371 | | | | |
| 2372 | +-+---+---+-+ |
| 2373 | | Host B | |
| 2374 | +-----------+ |
| 2375 | |
| 2376 | In this configuration, the switches are isolated from one |
| 2377 | another. One reason to employ a topology such as this is for an |
| 2378 | isolated network with many hosts (a cluster configured for high |
| 2379 | performance, for example), using multiple smaller switches can be more |
| 2380 | cost effective than a single larger switch, e.g., on a network with 24 |
| 2381 | hosts, three 24 port switches can be significantly less expensive than |
| 2382 | a single 72 port switch. |
| 2383 | |
| 2384 | If access beyond the network is required, an individual host |
| 2385 | can be equipped with an additional network device connected to an |
| 2386 | external network; this host then additionally acts as a gateway. |
| 2387 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2388 | 12.2.1 MT Bonding Mode Selection for Multiple Switch Topology |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2389 | ------------------------------------------------------------- |
| 2390 | |
| 2391 | In actual practice, the bonding mode typically employed in |
| 2392 | configurations of this type is balance-rr. Historically, in this |
| 2393 | network configuration, the usual caveats about out of order packet |
| 2394 | delivery are mitigated by the use of network adapters that do not do |
| 2395 | any kind of packet coalescing (via the use of NAPI, or because the |
| 2396 | device itself does not generate interrupts until some number of |
| 2397 | packets has arrived). When employed in this fashion, the balance-rr |
| 2398 | mode allows individual connections between two hosts to effectively |
| 2399 | utilize greater than one interface's bandwidth. |
| 2400 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2401 | 12.2.2 MT Link Monitoring for Multiple Switch Topology |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2402 | ------------------------------------------------------ |
| 2403 | |
| 2404 | Again, in actual practice, the MII monitor is most often used |
| 2405 | in this configuration, as performance is given preference over |
| 2406 | availability. The ARP monitor will function in this topology, but its |
| 2407 | advantages over the MII monitor are mitigated by the volume of probes |
| 2408 | needed as the number of systems involved grows (remember that each |
| 2409 | host in the network is configured with bonding). |
| 2410 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2411 | 13. Switch Behavior Issues |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2412 | ========================== |
| 2413 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2414 | 13.1 Link Establishment and Failover Delays |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2415 | ------------------------------------------- |
| 2416 | |
| 2417 | Some switches exhibit undesirable behavior with regard to the |
| 2418 | timing of link up and down reporting by the switch. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2419 | |
| 2420 | First, when a link comes up, some switches may indicate that |
| 2421 | the link is up (carrier available), but not pass traffic over the |
| 2422 | interface for some period of time. This delay is typically due to |
| 2423 | some type of autonegotiation or routing protocol, but may also occur |
| 2424 | during switch initialization (e.g., during recovery after a switch |
| 2425 | failure). If you find this to be a problem, specify an appropriate |
| 2426 | value to the updelay bonding module option to delay the use of the |
| 2427 | relevant interface(s). |
| 2428 | |
| 2429 | Second, some switches may "bounce" the link state one or more |
| 2430 | times while a link is changing state. This occurs most commonly while |
| 2431 | the switch is initializing. Again, an appropriate updelay value may |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2432 | help. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2433 | |
| 2434 | Note that when a bonding interface has no active links, the |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2435 | driver will immediately reuse the first link that goes up, even if the |
| 2436 | updelay parameter has been specified (the updelay is ignored in this |
| 2437 | case). If there are slave interfaces waiting for the updelay timeout |
| 2438 | to expire, the interface that first went into that state will be |
| 2439 | immediately reused. This reduces down time of the network if the |
| 2440 | value of updelay has been overestimated, and since this occurs only in |
| 2441 | cases with no connectivity, there is no additional penalty for |
| 2442 | ignoring the updelay. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2443 | |
| 2444 | In addition to the concerns about switch timings, if your |
| 2445 | switches take a long time to go into backup mode, it may be desirable |
| 2446 | to not activate a backup interface immediately after a link goes down. |
| 2447 | Failover may be delayed via the downdelay bonding module option. |
| 2448 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2449 | 13.2 Duplicated Incoming Packets |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2450 | -------------------------------- |
| 2451 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 2452 | NOTE: Starting with version 3.0.2, the bonding driver has logic to |
| 2453 | suppress duplicate packets, which should largely eliminate this problem. |
| 2454 | The following description is kept for reference. |
| 2455 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2456 | It is not uncommon to observe a short burst of duplicated |
| 2457 | traffic when the bonding device is first used, or after it has been |
| 2458 | idle for some period of time. This is most easily observed by issuing |
| 2459 | a "ping" to some other host on the network, and noticing that the |
| 2460 | output from ping flags duplicates (typically one per slave). |
| 2461 | |
| 2462 | For example, on a bond in active-backup mode with five slaves |
| 2463 | all connected to one switch, the output may appear as follows: |
| 2464 | |
| 2465 | # ping -n 10.0.4.2 |
| 2466 | PING 10.0.4.2 (10.0.4.2) from 10.0.3.10 : 56(84) bytes of data. |
| 2467 | 64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.7 ms |
| 2468 | 64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) |
| 2469 | 64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) |
| 2470 | 64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) |
| 2471 | 64 bytes from 10.0.4.2: icmp_seq=1 ttl=64 time=13.8 ms (DUP!) |
| 2472 | 64 bytes from 10.0.4.2: icmp_seq=2 ttl=64 time=0.216 ms |
| 2473 | 64 bytes from 10.0.4.2: icmp_seq=3 ttl=64 time=0.267 ms |
| 2474 | 64 bytes from 10.0.4.2: icmp_seq=4 ttl=64 time=0.222 ms |
| 2475 | |
| 2476 | This is not due to an error in the bonding driver, rather, it |
| 2477 | is a side effect of how many switches update their MAC forwarding |
| 2478 | tables. Initially, the switch does not associate the MAC address in |
| 2479 | the packet with a particular switch port, and so it may send the |
| 2480 | traffic to all ports until its MAC forwarding table is updated. Since |
| 2481 | the interfaces attached to the bond may occupy multiple ports on a |
| 2482 | single switch, when the switch (temporarily) floods the traffic to all |
| 2483 | ports, the bond device receives multiple copies of the same packet |
| 2484 | (one per slave device). |
| 2485 | |
| 2486 | The duplicated packet behavior is switch dependent, some |
| 2487 | switches exhibit this, and some do not. On switches that display this |
| 2488 | behavior, it can be induced by clearing the MAC forwarding table (on |
| 2489 | most Cisco switches, the privileged command "clear mac address-table |
| 2490 | dynamic" will accomplish this). |
| 2491 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2492 | 14. Hardware Specific Considerations |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2493 | ==================================== |
| 2494 | |
| 2495 | This section contains additional information for configuring |
| 2496 | bonding on specific hardware platforms, or for interfacing bonding |
| 2497 | with particular switches or other devices. |
| 2498 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2499 | 14.1 IBM BladeCenter |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2500 | -------------------- |
| 2501 | |
| 2502 | This applies to the JS20 and similar systems. |
| 2503 | |
| 2504 | On the JS20 blades, the bonding driver supports only |
| 2505 | balance-rr, active-backup, balance-tlb and balance-alb modes. This is |
| 2506 | largely due to the network topology inside the BladeCenter, detailed |
| 2507 | below. |
| 2508 | |
| 2509 | JS20 network adapter information |
| 2510 | -------------------------------- |
| 2511 | |
| 2512 | All JS20s come with two Broadcom Gigabit Ethernet ports |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2513 | integrated on the planar (that's "motherboard" in IBM-speak). In the |
| 2514 | BladeCenter chassis, the eth0 port of all JS20 blades is hard wired to |
| 2515 | I/O Module #1; similarly, all eth1 ports are wired to I/O Module #2. |
| 2516 | An add-on Broadcom daughter card can be installed on a JS20 to provide |
| 2517 | two more Gigabit Ethernet ports. These ports, eth2 and eth3, are |
| 2518 | wired to I/O Modules 3 and 4, respectively. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2519 | |
| 2520 | Each I/O Module may contain either a switch or a passthrough |
| 2521 | module (which allows ports to be directly connected to an external |
| 2522 | switch). Some bonding modes require a specific BladeCenter internal |
| 2523 | network topology in order to function; these are detailed below. |
| 2524 | |
| 2525 | Additional BladeCenter-specific networking information can be |
| 2526 | found in two IBM Redbooks (www.ibm.com/redbooks): |
| 2527 | |
| 2528 | "IBM eServer BladeCenter Networking Options" |
| 2529 | "IBM eServer BladeCenter Layer 2-7 Network Switching" |
| 2530 | |
| 2531 | BladeCenter networking configuration |
| 2532 | ------------------------------------ |
| 2533 | |
| 2534 | Because a BladeCenter can be configured in a very large number |
| 2535 | of ways, this discussion will be confined to describing basic |
| 2536 | configurations. |
| 2537 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2538 | Normally, Ethernet Switch Modules (ESMs) are used in I/O |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2539 | modules 1 and 2. In this configuration, the eth0 and eth1 ports of a |
| 2540 | JS20 will be connected to different internal switches (in the |
| 2541 | respective I/O modules). |
| 2542 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2543 | A passthrough module (OPM or CPM, optical or copper, |
| 2544 | passthrough module) connects the I/O module directly to an external |
| 2545 | switch. By using PMs in I/O module #1 and #2, the eth0 and eth1 |
| 2546 | interfaces of a JS20 can be redirected to the outside world and |
| 2547 | connected to a common external switch. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2548 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2549 | Depending upon the mix of ESMs and PMs, the network will |
| 2550 | appear to bonding as either a single switch topology (all PMs) or as a |
| 2551 | multiple switch topology (one or more ESMs, zero or more PMs). It is |
| 2552 | also possible to connect ESMs together, resulting in a configuration |
| 2553 | much like the example in "High Availability in a Multiple Switch |
| 2554 | Topology," above. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2555 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2556 | Requirements for specific modes |
| 2557 | ------------------------------- |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2558 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2559 | The balance-rr mode requires the use of passthrough modules |
| 2560 | for devices in the bond, all connected to an common external switch. |
| 2561 | That switch must be configured for "etherchannel" or "trunking" on the |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2562 | appropriate ports, as is usual for balance-rr. |
| 2563 | |
| 2564 | The balance-alb and balance-tlb modes will function with |
| 2565 | either switch modules or passthrough modules (or a mix). The only |
| 2566 | specific requirement for these modes is that all network interfaces |
| 2567 | must be able to reach all destinations for traffic sent over the |
| 2568 | bonding device (i.e., the network must converge at some point outside |
| 2569 | the BladeCenter). |
| 2570 | |
| 2571 | The active-backup mode has no additional requirements. |
| 2572 | |
| 2573 | Link monitoring issues |
| 2574 | ---------------------- |
| 2575 | |
| 2576 | When an Ethernet Switch Module is in place, only the ARP |
| 2577 | monitor will reliably detect link loss to an external switch. This is |
| 2578 | nothing unusual, but examination of the BladeCenter cabinet would |
| 2579 | suggest that the "external" network ports are the ethernet ports for |
| 2580 | the system, when it fact there is a switch between these "external" |
| 2581 | ports and the devices on the JS20 system itself. The MII monitor is |
| 2582 | only able to detect link failures between the ESM and the JS20 system. |
| 2583 | |
| 2584 | When a passthrough module is in place, the MII monitor does |
| 2585 | detect failures to the "external" port, which is then directly |
| 2586 | connected to the JS20 system. |
| 2587 | |
| 2588 | Other concerns |
| 2589 | -------------- |
| 2590 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2591 | The Serial Over LAN (SoL) link is established over the primary |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2592 | ethernet (eth0) only, therefore, any loss of link to eth0 will result |
| 2593 | in losing your SoL connection. It will not fail over with other |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2594 | network traffic, as the SoL system is beyond the control of the |
| 2595 | bonding driver. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2596 | |
| 2597 | It may be desirable to disable spanning tree on the switch |
| 2598 | (either the internal Ethernet Switch Module, or an external switch) to |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2599 | avoid fail-over delay issues when using bonding. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2600 | |
| 2601 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2602 | 15. Frequently Asked Questions |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2603 | ============================== |
| 2604 | |
| 2605 | 1. Is it SMP safe? |
| 2606 | |
| 2607 | Yes. The old 2.0.xx channel bonding patch was not SMP safe. |
| 2608 | The new driver was designed to be SMP safe from the start. |
| 2609 | |
| 2610 | 2. What type of cards will work with it? |
| 2611 | |
| 2612 | Any Ethernet type cards (you can even mix cards - a Intel |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2613 | EtherExpress PRO/100 and a 3com 3c905b, for example). For most modes, |
| 2614 | devices need not be of the same speed. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2615 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 2616 | Starting with version 3.2.1, bonding also supports Infiniband |
| 2617 | slaves in active-backup mode. |
| 2618 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2619 | 3. How many bonding devices can I have? |
| 2620 | |
| 2621 | There is no limit. |
| 2622 | |
| 2623 | 4. How many slaves can a bonding device have? |
| 2624 | |
| 2625 | This is limited only by the number of network interfaces Linux |
| 2626 | supports and/or the number of network cards you can place in your |
| 2627 | system. |
| 2628 | |
| 2629 | 5. What happens when a slave link dies? |
| 2630 | |
| 2631 | If link monitoring is enabled, then the failing device will be |
| 2632 | disabled. The active-backup mode will fail over to a backup link, and |
| 2633 | other modes will ignore the failed link. The link will continue to be |
| 2634 | monitored, and should it recover, it will rejoin the bond (in whatever |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2635 | manner is appropriate for the mode). See the sections on High |
| 2636 | Availability and the documentation for each mode for additional |
| 2637 | information. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2638 | |
| 2639 | Link monitoring can be enabled via either the miimon or |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2640 | arp_interval parameters (described in the module parameters section, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2641 | above). In general, miimon monitors the carrier state as sensed by |
| 2642 | the underlying network device, and the arp monitor (arp_interval) |
| 2643 | monitors connectivity to another host on the local network. |
| 2644 | |
| 2645 | If no link monitoring is configured, the bonding driver will |
| 2646 | be unable to detect link failures, and will assume that all links are |
| 2647 | always available. This will likely result in lost packets, and a |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2648 | resulting degradation of performance. The precise performance loss |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2649 | depends upon the bonding mode and network configuration. |
| 2650 | |
| 2651 | 6. Can bonding be used for High Availability? |
| 2652 | |
| 2653 | Yes. See the section on High Availability for details. |
| 2654 | |
| 2655 | 7. Which switches/systems does it work with? |
| 2656 | |
| 2657 | The full answer to this depends upon the desired mode. |
| 2658 | |
| 2659 | In the basic balance modes (balance-rr and balance-xor), it |
| 2660 | works with any system that supports etherchannel (also called |
| 2661 | trunking). Most managed switches currently available have such |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2662 | support, and many unmanaged switches as well. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2663 | |
| 2664 | The advanced balance modes (balance-tlb and balance-alb) do |
| 2665 | not have special switch requirements, but do need device drivers that |
| 2666 | support specific features (described in the appropriate section under |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2667 | module parameters, above). |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2668 | |
Auke Kok | 6224e01 | 2006-06-08 11:15:35 -0700 | [diff] [blame] | 2669 | In 802.3ad mode, it works with systems that support IEEE |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2670 | 802.3ad Dynamic Link Aggregation. Most managed and many unmanaged |
| 2671 | switches currently available support 802.3ad. |
| 2672 | |
| 2673 | The active-backup mode should work with any Layer-II switch. |
| 2674 | |
| 2675 | 8. Where does a bonding device get its MAC address from? |
| 2676 | |
Jay Vosburgh | 9a6c686 | 2007-11-13 20:25:48 -0800 | [diff] [blame] | 2677 | When using slave devices that have fixed MAC addresses, or when |
| 2678 | the fail_over_mac option is enabled, the bonding device's MAC address is |
| 2679 | the MAC address of the active slave. |
| 2680 | |
| 2681 | For other configurations, if not explicitly configured (with |
| 2682 | ifconfig or ip link), the MAC address of the bonding device is taken from |
| 2683 | its first slave device. This MAC address is then passed to all following |
| 2684 | slaves and remains persistent (even if the first slave is removed) until |
| 2685 | the bonding device is brought down or reconfigured. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2686 | |
| 2687 | If you wish to change the MAC address, you can set it with |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2688 | ifconfig or ip link: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2689 | |
| 2690 | # ifconfig bond0 hw ether 00:11:22:33:44:55 |
| 2691 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2692 | # ip link set bond0 address 66:77:88:99:aa:bb |
| 2693 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2694 | The MAC address can be also changed by bringing down/up the |
| 2695 | device and then changing its slaves (or their order): |
| 2696 | |
| 2697 | # ifconfig bond0 down ; modprobe -r bonding |
| 2698 | # ifconfig bond0 .... up |
| 2699 | # ifenslave bond0 eth... |
| 2700 | |
| 2701 | This method will automatically take the address from the next |
| 2702 | slave that is added. |
| 2703 | |
| 2704 | To restore your slaves' MAC addresses, you need to detach them |
| 2705 | from the bond (`ifenslave -d bond0 eth0'). The bonding driver will |
| 2706 | then restore the MAC addresses that the slaves had before they were |
| 2707 | enslaved. |
| 2708 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2709 | 16. Resources and Links |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2710 | ======================= |
| 2711 | |
Nicolas de Pesloüan | a23c37f1 | 2011-03-13 10:34:22 +0000 | [diff] [blame] | 2712 | The latest version of the bonding driver can be found in the latest |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2713 | version of the linux kernel, found on http://kernel.org |
| 2714 | |
Nicolas de Pesloüan | a23c37f1 | 2011-03-13 10:34:22 +0000 | [diff] [blame] | 2715 | The latest version of this document can be found in the latest kernel |
| 2716 | source (named Documentation/networking/bonding.txt). |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2717 | |
Nicolas de Pesloüan | a23c37f1 | 2011-03-13 10:34:22 +0000 | [diff] [blame] | 2718 | Discussions regarding the usage of the bonding driver take place on the |
| 2719 | bonding-devel mailing list, hosted at sourceforge.net. If you have questions or |
| 2720 | problems, post them to the list. The list address is: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2721 | |
| 2722 | bonding-devel@lists.sourceforge.net |
| 2723 | |
Jay Vosburgh | 00354cf | 2005-07-21 12:18:02 -0700 | [diff] [blame] | 2724 | The administrative interface (to subscribe or unsubscribe) can |
| 2725 | be found at: |
| 2726 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2727 | https://lists.sourceforge.net/lists/listinfo/bonding-devel |
| 2728 | |
Rick Jones | f8b72d3 | 2012-07-20 10:51:37 +0000 | [diff] [blame] | 2729 | Discussions regarding the development of the bonding driver take place |
Nicolas de Pesloüan | a23c37f1 | 2011-03-13 10:34:22 +0000 | [diff] [blame] | 2730 | on the main Linux network mailing list, hosted at vger.kernel.org. The list |
| 2731 | address is: |
| 2732 | |
| 2733 | netdev@vger.kernel.org |
| 2734 | |
| 2735 | The administrative interface (to subscribe or unsubscribe) can |
| 2736 | be found at: |
| 2737 | |
| 2738 | http://vger.kernel.org/vger-lists.html#netdev |
| 2739 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2740 | Donald Becker's Ethernet Drivers and diag programs may be found at : |
Justin P. Mattock | 0ea6e61 | 2010-07-23 20:51:24 -0700 | [diff] [blame] | 2741 | - http://web.archive.org/web/*/http://www.scyld.com/network/ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2742 | |
| 2743 | You will also find a lot of information regarding Ethernet, NWay, MII, |
| 2744 | etc. at www.scyld.com. |
| 2745 | |
| 2746 | -- END -- |