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Diffstat (limited to 'doc/bird.sgml')
| -rw-r--r-- | doc/bird.sgml | 57 |
1 files changed, 45 insertions, 12 deletions
diff --git a/doc/bird.sgml b/doc/bird.sgml index 87113fa..8fa55f8 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. <p>BIRD supports all requirements of the BGP4 standard as defined in -RFC 1771<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc1771.txt"> -including several enhancements from the -latest draft<htmlurl url="ftp://ftp.rfc-editor.org/internet-drafts/draft-ietf-idr-bgp4-09.txt">. -It also supports the community attributes as per -RFC 1997<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc1997.txt">, -capability negotiation defined in -RFC 2842<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc2842.txt">. +RFC 4271<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4271.txt"> +It also supports the community attributes +(RFC 1997<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc1997.txt">), +capability negotiation +(RFC 3392<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc3392.txt">), +MD5 password authentication +(RFC 2385<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc2385.txt">), +route reflectors +(RFC 4456<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4456.txt">), +and 4B AS numbers +(RFC 4893<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4893.txt">). + + For IPv6, it uses the standard multiprotocol extensions defined in RFC 2283<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc2283.txt"> 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. + <tag>password <m/string/</tag> Use this password for MD5 authentication + of BGP sessions. Default: no authentication. + + <tag>rr client</tag> Be a route reflector and treat neighbor as + route reflection client. Default: disabled. + + <tag>rr cluster id <m/IPv4 address/</tag> 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. + + <tag>enable as4 <m/switch/</tag> 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. + <tag>disable after error <m/switch/</tag> 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. @@ -757,7 +784,7 @@ for each neighbor using the following configuration parameters: <tag>default bgp_med <m/number/</tag> Value of the Multiple Exit Discriminator to be used during route selection when the MED attribute - is missing. Default: infinite. + is missing. Default: 0. <tag>default bgp_local_pref <m/number/</tag> Value of the Local Preference to be used during route selection when the Local Preference attribute @@ -779,10 +806,16 @@ with `<tt/O/') are optional. selection among multiple BGP routes (see the selection rules above). It's used as an additional metric which is propagated through the whole local AS. - <tag>int <cf/bgp_med/ [IO]</tag> 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. + <tag>int <cf/bgp_med/ [O]</tag> 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<htmlurl url="ftp://ftp.rfc-editor.org/in-notes/rfc4451.txt"> + for further discussion of BGP MED attribute. <tag>enum <cf/bgp_origin/</tag> Origin of the route: either <cf/ORIGIN_IGP/ if the route has originated in an interior routing protocol or |