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Diffstat (limited to 'doc/bird.sgml')
| -rw-r--r-- | doc/bird.sgml | 86 |
1 files changed, 49 insertions, 37 deletions
diff --git a/doc/bird.sgml b/doc/bird.sgml index 46d2e026..269743d5 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -256,7 +256,10 @@ which allows you to talk with BIRD in an extensive way. <p>In the config, everything on a line after <cf/#/ or inside <cf>/* */</cf> is a comment, whitespace characters are treated as a single space. If there's a variable number of options, they are grouped using the <cf/{ }/ brackets. Each option is terminated by a <cf/;/. Configuration -is case sensitive. +is case sensitive. There are two ways how to name symbols (like protocol names, filter names, constats etc.). You can either use +a simple string starting with a letter followed by any combination of letters and numbers (e.g. "R123", "myfilter", "bgp5") or you +can enclose the name into apostrophes (<cf/'/) and than you can use any combination of numbers, letters. hyphens, dots and colons +(e.g. "'1:strange-name'", "'-NAME-'", "'cool::name'"). <p>Here is an example of a simple config file. It enables synchronization of routing tables with OS kernel, scans for @@ -377,7 +380,7 @@ protocol rip { "<m/format1/" is a format string using <it/strftime(3)/ notation (see <it/man strftime/ for details). <m/limit> and "<m/format2/" allow to specify the second format string for - times in past deeper than <m/limit/ seconds. There are two + times in past deeper than <m/limit/ seconds. There are few shorthands: <cf/iso long/ is a ISO 8601 date/time format (YYYY-MM-DD hh:mm:ss) that can be also specified using <cf/"%F %T"/. <cf/iso short/ is a variant of ISO 8601 that uses just @@ -385,11 +388,15 @@ protocol rip { the past) and the date format (YYYY-MM-DD) for far times. This is a shorthand for <cf/"%T" 72000 "%F"/. - By default, BIRD uses an short, ad-hoc format for <cf/route/ - and <cf/protocol/ times, and a <cf/iso long/ similar format - (DD-MM-YYYY hh:mm:ss) for <cf/base/ and <cf/log/. These - defaults are here for a compatibility with older versions - and might change in the future. + By default, BIRD uses the <cf/iso short/ format for <cf/route/ and + <cf/protocol/ times, and the <cf/iso long/ format for <cf/base/ and + <cf/log/ times. + + In pre-1.4.0 versions, BIRD used an short, ad-hoc format for + <cf/route/ and <cf/protocol/ times, and a <cf/iso long/ similar format + (DD-MM-YYYY hh:mm:ss) for <cf/base/ and <cf/log/. These timeformats + could be set by <cf/old short/ and <cf/old long/ compatibility + shorthands. <tag>table <m/name/ [sorted]</tag> Create a new routing table. The default routing table is @@ -922,9 +929,10 @@ incompatible with each other (that is to prevent you from shooting in the foot). <cf/true/ and <cf/false/. Boolean is the only type you can use in <cf/if/ statements. - <tag/int/ This is a general integer type, you can expect it to store - signed values from -2000000000 to +2000000000. Overflows are not - checked. You can use <cf/0x1234/ syntax to write hexadecimal values. + <tag/int/ This is a general integer type. It is an unsigned 32bit type; + i.e., you can expect it to store values from 0 to 4294967295. + Overflows are not checked. You can use <cf/0x1234/ syntax to write + hexadecimal values. <tag/pair/ This is a pair of two short integers. Each component can have values from 0 to 65535. Literals of this type are written as @@ -1532,33 +1540,37 @@ This allows to set routing policy and all the other parameters differently for each neighbor using the following configuration parameters: <descrip> - <tag>local [<m/ip/] as <m/number/</tag> Define which AS we - are part of. (Note that contrary to other IP routers, BIRD is - able to act as a router located in multiple AS'es - simultaneously, but in such cases you need to tweak the BGP - paths manually in the filters to get consistent behavior.) - Optional <cf/ip/ argument specifies a source address, - equivalent to the <cf/source address/ option (see below). + <tag>local [<m/ip/] as <m/number/</tag> Define which AS we are part + of. (Note that contrary to other IP routers, BIRD is able to act as a + router located in multiple AS'es simultaneously, but in such cases you + need to tweak the BGP paths manually in the filters to get consistent + behavior.) Optional <cf/ip/ argument specifies a source address, + equivalent to the <cf/source address/ option (see below). This + parameter is mandatory. + + <tag>neighbor <m/ip/ as <m/number/</tag> Define neighboring router this + instance will be talking to and what AS it's located in. In case the + neighbor is in the same AS as we are, we automatically switch to iBGP. This parameter is mandatory. - <tag>neighbor <m/ip/ as <m/number/</tag> Define neighboring router - this instance will be talking to and what AS it's located in. Unless - you use the <cf/multihop/ clause, it must be directly connected to one - of your router's interfaces. In case the neighbor is in the same AS - as we are, we automatically switch to iBGP. This parameter is mandatory. - - <tag>multihop [<m/number/]</tag> Configure multihop BGP - session to a neighbor that isn't directly connected. - Accurately, this option should be used if the configured - neighbor IP address does not match with any local network - subnets. Such IP address have to be reachable through system - routing table. For multihop BGP it is recommended to - explicitly configure <cf/source address/ to have it - stable. Optional <cf/number/ argument can be used to specify - the number of hops (used for TTL). Note that the number of - networks (edges) in a path is counted, i.e. if two BGP - speakers are separated by one router, the number of hops is - 2. Default: switched off. + <tag>direct</tag> Specify that the neighbor is directly connected. The + IP address of the neighbor must be from a directly reachable IP range + (i.e. associated with one of your router's interfaces), otherwise the + BGP session wouldn't start but it would wait for such interface to + appear. The alternative is the <cf/multihop/ option. Default: enabled + for eBGP. + + <tag>multihop [<m/number/]</tag> Configure multihop BGP session to a + neighbor that isn't directly connected. Accurately, this option should + be used if the configured neighbor IP address does not match with any + local network subnets. Such IP address have to be reachable through + system routing table. The alternative is the <cf/direct/ option. For + multihop BGP it is recommended to explicitly configure the source + address to have it stable. Optional <cf/number/ argument can be used to + specify the number of hops (used for TTL). Note that the number of + networks (edges) in a path is counted; i.e., if two BGP speakers are + separated by one router, the number of hops is 2. Default: enabled for + iBGP. <tag>source address <m/ip/</tag> Define local address we should use for next hop calculation and as a source address @@ -1605,8 +1617,8 @@ for each neighbor using the following configuration parameters: table, and was used in older versions of BIRD, but does not handle well nontrivial iBGP setups and multihop. Recursive mode is incompatible with <ref id="dsc-sorted" name="sorted - tables">. Default: <cf/direct/ for singlehop eBGP, - <cf/recursive/ otherwise. + tables">. Default: <cf/direct/ for direct sessions, + <cf/recursive/ for multihop sessions. <tag>igp table <m/name/</tag> Specifies a table that is used as an IGP routing table. Default: the same as the table BGP is |