From 6bcef22580010aec695fb2b559c7b33ee00261b0 Mon Sep 17 00:00:00 2001 From: Ondrej Zajicek Date: Sat, 19 Mar 2011 12:13:59 +0100 Subject: Documentation for the router advertisement protocol. --- doc/bird.sgml | 153 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 149 insertions(+), 4 deletions(-) (limited to 'doc') diff --git a/doc/bird.sgml b/doc/bird.sgml index 5d9c7bd..7b6e97a 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -79,6 +79,7 @@ protocols to be incorporated easily. Among other features, BIRD supports: the Border Gateway Protocol (BGPv4) the Routing Information Protocol (RIPv2) the Open Shortest Path First protocol (OSPFv2, OSPFv3) + the Router Advertisements for IPv6 hosts a virtual protocol for exchange of routes between different routing tables on a single host a command-line interface allowing on-line control and inspection of status of the daemon @@ -385,7 +386,8 @@ to zero to disable it. An empty is equivalent to is equivalent to Configuration

In the main part of configuration, there can be multiple definitions of -OSPF area witch different id included. These definitions includes many other +OSPF areas, each with a different id. These definitions includes many other switches and multiple definitions of interfaces. Definition of interface may contain many switches and constant definitions and list of neighbors on nonbroadcast networks. @@ -1967,6 +1969,149 @@ protocol pipe { # The Pipe } +RAdv + +Introduction + +

The RAdv protocol is an implementation of Router Advertisements, +which are used in the IPv6 stateless autoconfiguration. IPv6 routers +send (in irregular time intervals or as an answer to a request) +advertisement packets to connected networks. These packets contain +basic information about a local network (e.g. a list of network +prefixes), which allows network hosts to autoconfigure network +addresses and choose a default route. BIRD implements router behavior +as defined in RFC 4861. + +Configuration + +

There are two classes of definitions in RAdv configuration -- +interface definitions and prefix definitions: + + + interface + Interface definitions specify a set of interfaces on which the + protocol is activated and contain interface specific options. + See common options for + detailed description. + + prefix + Prefix definitions allows to modify a list of advertised + prefixes. By default, the advertised prefixes are the same as + the network prefixes assigned to the interface. For each + network prefix, the matching prefix definition is found and + its options are used. If no matching prefix definition is + found, the prefix is used with default options. + + Prefix definitions can be either global or interface-specific. + The second ones are part of interface options. The prefix + definition matching is done in the first-match style, when + interface-specific definitions are processed before global + definitions. As expected, the prefix definition is matching if + the network prefix is a subnet of the prefix in prefix + definition. + + +

Interface specific options: + + + max ra interval + Unsolicited router advertisements are sent in irregular time + intervals. This option specifies the maximum length of these + intervals, in seconds. Valid values are 4-1800. Default: 600 + + min ra interval + This option specifies the minimum length of that intervals, in + seconds. Must be at least 3 and at most 3/4 * max ra interval. + Default: about 1/3 * max ra interval. + + min delay + The minimum delay between two consecutive router advertisements, + in seconds. Default: 3 + + managed + This option specifies whether hosts should use DHCPv6 for + IP address configuration. Default: no + + other config + This option specifies whether hosts should use DHCPv6 to + receive other configuration information. Default: no + + link mtu + This option specifies which value of MTU should be used by + hosts. 0 means unspecified. Default: 0 + + reachable time + This option specifies the time (in milliseconds) how long + hosts should assume a neighbor is reachable (from the last + confirmation). Maximum is 3600000, 0 means unspecified. + Default 0. + + retrans timer + This option specifies the time (in milliseconds) how long + hosts should wait before retransmitting Neighbor Solicitation + messages. 0 means unspecified. Default 0. + + current hop limit + This option specifies which value of Hop Limit should be used + by hosts. Valid values are 0-255, 0 means unspecified. Default: 64 + + default lifetime + This option specifies the time (in seconds) how long (after + the receipt of RA) hosts may use the router as a default + router. 0 means do not use as a default router. Default: 3 * + max ra interval. + + + +

Prefix specific options: + + + onlink + This option specifies whether hosts may use the advertised + prefix for onlink determination. Default: yes + + autonomous + This option specifies whether hosts may use the advertised + prefix for stateless autoconfiguration. Default: yes + + valid lifetime + This option specifies the time (in seconds) how long (after + the receipt of RA) the prefix information is valid, i.e., + autoconfigured IP addresses can be assigned and hosts with + that IP addresses are considered directly reachable. 0 means + the prefix is no longer valid. Default: 86400 (1 day) + + preferred lifetime + This option specifies the time (in seconds) how long (after + the receipt of RA) IP addresses generated from the prefix + using stateless autoconfiguration remain preferred. Default: + 14400 (4 hours) + + +Example + +

+protocol radv { + interface "eth2" { + max ra interval 5; # Fast failover with more routers + managed yes; # Using DHCPv6 on eth2 + prefix ::/0 { + autonomous off; # So do not autoconfigure any IP + }; + }; + + interface "eth*"; # No need for any other options + + prefix 2001:0DB8:1234::/48 { + preferred lifetime 0; # Deprecated address range + }; + + prefix 2001:0DB8:2000::/48 { + autonomous off; # Do not autoconfigure + }; +} + + RIP Introduction -- cgit v1.2.3