| <refentry id="rdisc"> |
| |
| <refmeta> |
| <refentrytitle>rdisc</refentrytitle> |
| <manvolnum>8</manvolnum> |
| <refmiscinfo>iputils-&snapshot;</refmiscinfo> |
| </refmeta> |
| |
| <refnamediv> |
| <refname>rdisc</refname> |
| <refpurpose>network router discovery daemon</refpurpose> |
| </refnamediv> |
| |
| <refsynopsisdiv> |
| <cmdsynopsis> |
| <command>rdisc</command> |
| <arg choice="opt"><option>-abdfrstvV</option></arg> |
| <arg choice="opt">-p <replaceable/preference/</arg> |
| <arg choice="opt">-T <replaceable/max_interval/</arg> |
| <arg choice="opt"><replaceable/send_address/</arg> |
| <arg choice="opt"><replaceable/receive_address/</arg> |
| </cmdsynopsis> |
| </refsynopsisdiv> |
| |
| <refsect1><title>DESCRIPTION</title> |
| <para> |
| <command/rdisc/ implements client side of the ICMP router discover protocol. |
| <command/rdisc/ is invoked at boot time to populate the network |
| routing tables with default routes. |
| </para> |
| |
| <para> |
| <command/rdisc/ listens on the ALL_HOSTS (224.0.0.1) multicast address |
| (or <replaceable/receive_address/ provided it is given) |
| for ROUTER_ADVERTISE messages from routers. The received |
| messages are handled by first ignoring those listed router addresses |
| with which the host does not share a network. Among the remaining addresses |
| the ones with the highest preference are selected as default routers |
| and a default route is entered in the kernel routing table |
| for each one of them. |
| </para> |
| |
| <para> |
| Optionally, <command/rdisc/ can avoid waiting for routers to announce |
| themselves by sending out a few ROUTER_SOLICITATION messages |
| to the ALL_ROUTERS (224.0.0.2) multicast address |
| (or <replaceable/send_address/ provided it is given) |
| when it is started. |
| </para> |
| |
| <para> |
| A timer is associated with each router address and the address will |
| no longer be considered for inclusion in the the routing tables if the |
| timer expires before a new |
| <emphasis/advertise/ message is received from the router. |
| The address will also be excluded from consideration if the host receives an |
| <emphasis/advertise/ |
| message with the preference being maximally negative. |
| </para> |
| |
| <para> |
| Server side of router discovery protocol is supported by Cisco IOS |
| and by any more or less complete UNIX routing daemon, f.e <command/gated/. |
| Or, <command/rdisc/ can act as responder, if compiled with -DRDISC_SERVER. |
| </para> |
| |
| </refsect1> |
| |
| <refsect1><title>OPTIONS</title> |
| |
| <variablelist> |
| <varlistentry> |
| <term><option/-a/</term> |
| <listitem><para> |
| Accept all routers independently of the preference they have in their |
| <emphasis/advertise/ messages. |
| Normally <command/rdisc/ only accepts (and enters in the kernel routing |
| tables) the router or routers with the highest preference. |
| </para></listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option/-b/</term> |
| <listitem><para> |
| Opposite to <option/-a/, i.e. install only router with the best |
| preference value. It is default behaviour. |
| </para></listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option/-d/</term> |
| <listitem><para> |
| Send debugging messages to syslog. |
| </para></listitem> |
| </varlistentry> |
| <varlistentry> |
| <term><option/-f/</term> |
| <listitem><para> |
| Run <command/rdisc/ forever even if no routers are found. |
| Normally <command/rdisc/ gives up if it has not received any |
| <emphasis/advertise/ message after after soliciting three times, |
| in which case it exits with a non-zero exit code. |
| If <option/-f/ is not specified in the first form then |
| <option/-s/ must be specified. |
| </para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option/-r/</term> |
| <listitem><para> |
| Responder mode, available only if compiled with -DRDISC_SERVER. |
| </para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option/-s/</term> |
| <listitem><para> |
| Send three <emphasis/solicitation/ messages initially to quickly discover |
| the routers when the system is booted. |
| When <option/-s/ is specified <command/rdisc/ |
| exits with a non-zero exit code if it can not find any routers. |
| This can be overridden with the <option/-f/ option. |
| </para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>-p <replaceable/preference/</option></term> |
| <listitem><para> |
| Set preference in advertisement. |
| Available only with -r option. |
| </para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option>-T <replaceable/max_interval/</option></term> |
| <listitem><para> |
| Set maximum advertisement interval in seconds. Default is 600 secs. |
| Available only with -r option. |
| </para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option/-t/</term> |
| <listitem><para> |
| Test mode. Do not go to background. |
| </para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option/-v/</term> |
| <listitem><para> |
| Be verbose i.e. send lots of debugging messages to syslog. |
| </para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><option/-V/</term> |
| <listitem><para> |
| Print version and exit. |
| </para></listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1><title>HISTORY</title> |
| <para> |
| This program was developed by Sun Microsystems (see copyright |
| notice in source file). It was ported to Linux by |
| <ulink url="mailto:kuznet@ms2.inr.ac.ru">Alexey Kuznetsov |
| <kuznet@ms2.inr.ac.ru></ulink>. |
| It is now maintained by |
| <ulink url="mailto:yoshfuji@skbuff.net">YOSHIFUJI Hideaki |
| <yoshfuji@skbuff.net></ulink>. |
| </para> |
| </refsect1> |
| |
| |
| <refsect1><title>SEE ALSO</title> |
| <para> |
| <citerefentry><refentrytitle/icmp/<manvolnum/7/</citerefentry>, |
| <citerefentry><refentrytitle/inet/<manvolnum/7/</citerefentry>, |
| <link linkend="ping"> |
| <citerefentry><refentrytitle/ping/<manvolnum/8/</citerefentry></link>. |
| </para> |
| </refsect1> |
| |
| <refsect1><title>REFERENCES</title> |
| <para> |
| Deering, S.E.,ed "ICMP Router Discovery Messages", |
| <ulink url="http://tools.ietf.org/rfc/rfc1256.txt"> |
| RFC1256</ulink>, Network Information Center, SRI International, |
| Menlo Park, Calif., September 1991. |
| </para> |
| </refsect1> |
| |
| <refsect1><title>SECURITY</title> |
| <para> |
| <command/rdisc/ requires <constant/CAP_NET_RAW/ to listen |
| and send ICMP messages and capability <constant/CAP_NET_ADMIN/ |
| to update routing tables. |
| </para> |
| </refsect1> |
| |
| <refsect1><title>AVAILABILITY</title> |
| <para> |
| <command/rdisc/ is part of <filename/iputils/ package |
| and the latest versions are available in source form at |
| <ulink url="http://www.skbuff.net/iputils/iputils-current.tar.bz2"> |
| http://www.skbuff.net/iputils/iputils-current.tar.bz2</ulink>. |
| </para> |
| </refsect1> |
| |
| <![IGNORE[ |
| <refsect1><title>COPYING</title> |
| <para> |
| <literallayout> |
| Rdisc (this program) was developed by Sun Microsystems, Inc. and is |
| provided for unrestricted use provided that this legend is included on |
| all tape media and as a part of the software program in whole or part. |
| Users may copy or modify Rdisc without charge, and they may freely |
| distribute it. |
| |
| RDISC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE |
| WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR |
| PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE. |
| |
| Rdisc is provided with no support and without any obligation on the |
| part of Sun Microsystems, Inc. to assist in its use, correction, |
| modification or enhancement. |
| |
| SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE |
| INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY RDISC |
| OR ANY PART THEREOF. |
| |
| In no event will Sun Microsystems, Inc. be liable for any lost revenue |
| or profits or other special, indirect and consequential damages, even if |
| Sun has been advised of the possibility of such damages. |
| |
| Sun Microsystems, Inc. |
| 2550 Garcia Avenue |
| Mountain View, California 94043 |
| </literallayout> |
| </para> |
| </refsect1> |
| ]]> |
| |
| |
| </refentry> |