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Diffstat (limited to 'doc/bird.sgml')
| -rw-r--r-- | doc/bird.sgml | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/doc/bird.sgml b/doc/bird.sgml index 666d9f62..8d8ec35e 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -1446,10 +1446,23 @@ and vice versa, depending on what's allowed by the filters. Export filters contr of routes from the primary table to the secondary one, import filters control the opposite direction. +<p>The Pipe protocol may work in the opaque mode or in the transparent +mode. In the opaque mode, thee Pipe protocol retransmits optimal route +from one table to the other table in a similar way like other +protocols send and receive routes. Retransmitted route will have the +source set to the Pipe protocol, which may limit access to protocol +specific route attributes. The opaque mode is a default mode. + +<p>In transparent mode, the Pipe protocol retransmits all routes from +one table to the other table, retaining their original source and +attributes. If import and export filters are set to accept, then both +tables would have the same content. The mode can be set by +<tt/mode/ option. + <p>The primary use of multiple routing tables and the Pipe protocol is for policy routing, where handling of a single packet doesn't depend only on its destination address, but also on its source address, source interface, protocol type and other similar parameters. -In many systems (Linux 2.2 being a good example), the kernel allows to enforce routing policies +In many systems (Linux being a good example), the kernel allows to enforce routing policies by defining routing rules which choose one of several routing tables to be used for a packet according to its parameters. Setting of these rules is outside the scope of BIRD's work (on Linux, you can use the <tt/ip/ command), but you can create several routing tables in BIRD, @@ -1460,8 +1473,10 @@ another one. <sect1>Configuration <p><descrip> - <tag>peer table <m/table/</tag> Define secondary routing table to connect to. The + <tag>peer table <m/table/</tag> Defines secondary routing table to connect to. The primary one is selected by the <cf/table/ keyword. + + <tag>mode opaque|transparent</tag> Specifies the mode for the pipe to work in. Default is opaque. </descrip> <sect1>Attributes |