man/man8/bridge.8

.TH BRIDGE 8 "1 August 2012" "iproute2" "Linux"
.SH NAME
bridge \- show / manipulate bridge addresses and devices
.SH SYNOPSIS

.ad l
.in +8
.ti -8
.B bridge
.RI "[ " OPTIONS " ] " OBJECT " { " COMMAND " | "
.BR help " }"
.sp

.ti -8
.IR OBJECT " := { "
.BR link " | " fdb " | " vlan " | " monitor " }"
.sp

.ti -8
.IR OPTIONS " := { "
\fB\-V\fR[\fIersion\fR] |
\fB\-s\fR[\fItatistics\fR] }

.ti -8
.BR "bridge link set"
.B  dev
.IR DEV
.IR " [ "
.B  cost
.IR COST " ] [ "
.B  priority
.IR PRIO " ]  [ "
.B  state
.IR STATE "] ["
.BR guard " { " on " | " off " } ] [ "
.BR hairpin " { " on " | " off " } ] [ "
.BR fastleave " { " on " | " off " } ] [ "
.BR root_block " { " on " | " off " } ] [ "
.BR hwmode " { " vepa " | " veb " } ] "

.ti -8
.BR "bridge link" " [ " show " ] [ "
.B  dev
.IR DEV " ]"

.ti -8
.BR "bridge fdb" " { " add " | " del " } "
.I LLADDR
.B  dev
.IR DEV " { "
.BR local " | " temp " } { "
.BR self " } { " embedded " } "

.ti -8
.BR "bridge fdb" " [ " show " ] [ "
.B  dev
.IR DEV " ]"

.ti -8
.BR "bridge vlan" " { " add " | " del " } "
.B  dev
.IR DEV
.B  vid 
.IR VID " [ "
.BR  pvid " ] [ " untagged " ]  [ "
.BR  self " ]  [ " master " ] "

.ti -8
.BR "bridge vlan" " [ " show " ] [ "
.B  dev
.IR DEV " ]"

.ti -8
.BR "bridge monitor" " [ " all " | " neigh " | " link " ]"

.SH OPTIONS

.TP
.BR "\-V" , " -Version"
print the version of the
.B bridge
utility and exit.

.TP
.BR "\-s" , " \-stats", " \-statistics"
output more information.  If this option
is given multiple times, the amount of information increases.
As a rule, the information is statistics or some time values.


.SH BRIDGE - COMMAND SYNTAX

.SS
.I OBJECT

.TP
.B link
- Bridge port.

.TP
.B fdb 
- Forwarding Database entry.

.TP
.B vlan
- VLAN filter list.

.SS
.I COMMAND

Specifies the action to perform on the object.
The set of possible actions depends on the object type.
As a rule, it is possible to
.BR "add" , " delete"
and
.B show
(or
.B list
) objects, but some objects do not allow all of these operations
or have some additional commands.  The
.B help
command is available for all objects.  It prints
out a list of available commands and argument syntax conventions.
.sp
If no command is given, some default command is assumed.
Usually it is
.B list
or, if the objects of this class cannot be listed,
.BR "help" .

.SH bridge link - bridge port

.B link
objects correspond to the port devices of the bridge.

.P
The corresponding commands set and display port status and bridge specific
attributes.

.SS bridge link set - set bridge specific attributes on a port

.TP
.BI dev " NAME "
interface name of the bridge port

.TP
.BI cost " COST "
the STP path cost of the specified port.

.TP
.BI priority " PRIO "
the STP port priority.  The priority value is an unsigned 8-bit quantity
(number between 0 and 255).  This metric is used in the designated port an
droot port selectio algorithms.

.TP
.BI state " STATE "
the operation state of the port.  This is primarily used by user space STP/RSTP
implementation.  The following is a list of valid values:

.B 0
- port is DISABLED.  Make this port completely inactive.
.sp

.B 1
- STP LISTENING state.  Only valid if STP is enabled on the brige.  In this
state the port for list for STP BPDUs and drop all other traffic.
.sp

.B 2
- STP LEARNING state.  Only valid if STP is enabled on the bridge.  In this
state the port will accept traffic only for the purpose of updating MAC
adress tables.
.sp

.B 3
- STP FORWARDING state.  Port is fully active.
.sp

.B 4
- STP BLOCKING state.  Only valid if STP is eanbled on the bridge.  This state
is used during the STP election process.  In this state, port will only process
STP BPDUs.
.sp

.TP
.BR "guard on " or " guard off "
Controls whether STP BPUDs will be processed by the bridge port.  By default,
the flag is turned off allowed BPDU processing.  Turning this flag on will
cause the port to stop processing STP BPDUs.

.TP
.BR "hairpin on " or " hairpin off "
Controls whether traffic may be send back out of the port on which it was
received.  By default, this flag is turned off and the bridge will not forward
traffic back out of the receiving port.

.TP
.BR "fastleave on " or " fastleave off "
This flag allows the bridge to immediately stop multicast traffic on a port
that recieves IGMP Leave message.  It is only used with IGMP snooping is
enabled on the bridge.  By default the flag is off.

.TP
.BR "root_block on " or " root_block off "
Controls whether a given port is allowed to become root port or not.  Only used
when STP is enabled on the bridge.  By default the flag is off.

.TP
.BI hwmode
Some network interface cards support HW bridge functionality and they may be
configured in different modes.  Currently support modes are:

.B vepa
- Data sent between HW ports is sent on the wire to the external
switch.

.B veb
- bridging happens in hardware.

.SS bridge link show - list bridge port configuration.

This command displays the current bridge port configuration and flags.

.SH bridge fdb - forwarding database management

.B fdb
objects contain known Ethernet addresses on a  link.

.P
The corresponding commands display fdb entries, add new entries,
and delete old ones.

.SS bridge fdb add - add a new fdb entry

This command creates a new fdb entry.

.TP
.BI "ADDRESS"
the Ethernet MAC address.

.TP
.BI dev " NAME"
the interface to which this address is associated.

.B self
- the address is associated with a software fdb (default)
.sp

.B embedded
- the address is associated with an offloaded fdb
.sp

.in -8

.SS bridge fdb delete - delete a forwarding database entry
This command removes an existing fdb entry.

.PP
The arguments are the same as with
.BR "bridge fdb add" ,

.SS bridge fdb show - list forwarding entries.

This command displays the current forwarding table.

.PP
With the
.B -statistics
option, the command becomes verbose.  It prints out the last updated
and last used time for each entry.

.SH bridge vlan - VLAN filter list

.B vlan
objects contain known VLAN IDs for a link.

.P
The corresponding commands display vlan filter entries, add new entries,
and delete old ones.

.SS bridge vlan add - add a new vlan filter entry

This command creates a new vlan filter entry.

.TP
.BI dev " NAME"
the interface with which this vlan is associated.

.TP
.BI vid " VID"
the VLAN ID that identifies the vlan.

.TP
.BI pvid
the vlan specified is to be considered a PVID at ingress.
Any untagged frames will be assigned to this VLAN.

.TP
.BI untagged
the vlan specified is to be treated as untagged on egress.

.TP
.BI self
the vlan is configured on the specified physical device.  Required if the
device is the bridge device.

.TP
.BI master
the vlan is configured on the sofware bridge (default).

.SS bridge vlan delete - delete a forwarding database entry
This command removes an existing fdb entry.

.PP
The arguments are the same as with
.BR "bridge vlan add".
The
.BR "pvid " and " untagged"
flags are ignored.

.SS bridge vlan show - list vlan configuration.

This command displays the current VLAN filter table.

.SH bridge monitor - state monitoring

The
.B bridge
utility can monitor the state of devices and  addresses
continuously.  This option has a slightly different format.
Namely, the
.B monitor
command is the first in the command line and then the object list follows:

.BR "bridge monitor" " [ " all " |"
.IR OBJECT-LIST " ]"

.I OBJECT-LIST
is the list of object types that we want to monitor.
It may contain
.BR link ",  and " fdb "."
If no
.B file
argument is given,
.B bridge
opens RTNETLINK, listens on it and dumps state changes in the format
described in previous sections.

.P
If a file name is given, it does not listen on RTNETLINK,
but opens the file containing RTNETLINK messages saved in binary format
and dumps them.  Such a history file can be generated with the


.SH NOTES
This command uses facilities added in Linux 3.0.

Although the forwarding table is maintained on a per-bridge device basis
the bridge device is not part of the syntax. This is a limitation of the
underlying netlink neighbour message protocol. When displaying the
forwarding table, entries for all bridges are displayed.
Add/delete/modify commands determine the underlying bridge device
based on the bridge to which the coresponding ethernet device is attached. 


.SH SEE ALSO
.BR ip (8)
.SH BUGS
.RB "Please direct bugreports and patches to: " <netdev@vger.kernel.org>

.SH AUTHOR
Original Manpage by Stephen Hemminger