From 1adc17b4b57267e301fcd67309494bbbddbfa718 Mon Sep 17 00:00:00 2001 From: Ondrej Zajicek Date: Sun, 26 Oct 2008 22:52:21 +0100 Subject: Update of a documentation - new options for AS4, MD5 auth and route reflection. --- doc/bird.conf.example | 3 +++ doc/bird.sgml | 41 ++++++++++++++++++++++++++++++++++------- 2 files changed, 37 insertions(+), 7 deletions(-) (limited to 'doc') diff --git a/doc/bird.conf.example b/doc/bird.conf.example index 05259d5..22221d4 100644 --- a/doc/bird.conf.example +++ b/doc/bird.conf.example @@ -179,6 +179,9 @@ protocol static { # default bgp_med 0; # MED value we use for comparison when none is defined # default bgp_local_pref 0; # The same for local preference # source address 62.168.0.14; # What local address we use for the TCP connection +# password "secret" # Password used for MD5 authentication +# rr client; # I am a route reflector and the neighor is my client +# rr cluster id 1.0.0.1 # Use this value for cluster id instead of my router id # export where source=RTS_STATIC; # export filter { # if source = RTS_STATIC then { diff --git a/doc/bird.sgml b/doc/bird.sgml index 87113fa..5ee9562 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -655,13 +655,19 @@ routing table it wishes to export along with complete path information route) in order to avoid routing loops.

BIRD supports all requirements of the BGP4 standard as defined in -RFC 1771 -including several enhancements from the -latest draft. -It also supports the community attributes as per -RFC 1997, -capability negotiation defined in -RFC 2842. +RFC 4271 +It also supports the community attributes +(RFC 1997), +capability negotiation +(RFC 3392), +MD5 password authentication +(RFC 2385), +route reflectors +(RFC 4456), +and 4B AS numbers +(RFC 4893). + + For IPv6, it uses the standard multiprotocol extensions defined in RFC 2283 including changes described in the @@ -721,6 +727,27 @@ for each neighbor using the following configuration parameters: for next hop calculation. Default: the address of the local end of the interface our neighbor is connected to. + password Use this password for MD5 authentication + of BGP sessions. Default: no authentication. + + rr client Be a route reflector and treat neighbor as + route reflection client. Default: disabled. + + rr cluster id Route reflectors use cluster id + to avoid route reflection loops. When there is one route reflector in a cluster + it usually uses its router id as a cluster id, but when there are more route + reflectors in a cluster, these need to be configured (using this option) to + use a common cluster id. Clients in a cluster need not known their cluster + id and this option is not allowed to them Default: a same as router id. + + enable as4 BGP protocol was designed to use 2B AS numbers + and was extended later to allow 4B AS number. BIRD supports 4B AS extension, + but by disabling this option it can be persuaded not to advertise it and + to maintain old-style sessions with its neighbors. This might be useful for + circumventing bugs in neighbor's implementation of 4B AS extension. + Even when disabled (off), BIRD behaves internally as AS4-aware BGP router. + Default: on. + disable after error When an error is encountered (either locally or by the other side), disable the instance automatically and wait for an administrator to fix the problem manually. Default: off. -- cgit v1.2.3 From b6bf284a905412cfe107b4967e55649e6194187e Mon Sep 17 00:00:00 2001 From: Ondrej Zajicek Date: Sun, 26 Oct 2008 22:59:21 +0100 Subject: Bugfixes in MULIT_EXIT_DISC attribute handling. - Old MED handling was completely different from behavior specified in RFCs - for example they havn't been propagated to neighboring areas. - Update tie-breaking according to RFC 4271. - Change default value for 'default bgp_med' configuration option according to RFC 4271. --- doc/bird.sgml | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'doc') diff --git a/doc/bird.sgml b/doc/bird.sgml index 5ee9562..8fa55f8 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -784,7 +784,7 @@ for each neighbor using the following configuration parameters: default bgp_med Value of the Multiple Exit Discriminator to be used during route selection when the MED attribute - is missing. Default: infinite. + is missing. Default: 0. default bgp_local_pref Value of the Local Preference to be used during route selection when the Local Preference attribute @@ -806,10 +806,16 @@ with `int The Multiple Exit Discriminator of the route - is an optional attribute which is often used within the local AS to - reflect interior distances to various boundary routers. See the route selection - rules above for exact semantics. + int The Multiple Exit Discriminator of the route + is an optional attribute which is used on on external (inter-AS) links to + convey to an adjacent AS the optimal entry point into the local AS. + The received attribute may be also propagated over internal BGP links + (and this is default behavior). The attribute value is zeroed when a route + is exported from a routing table to a BGP instance to ensure that the attribute + received from a neighboring AS is not propagated to other neighboring ASes. + A new value might be set in the export filter of a BGP instance. + See RFC 4451 + for further discussion of BGP MED attribute. enum Origin of the route: either