diff options
| author | Ondrej Zajicek (work) <santiago@crfreenet.org> | 2016-09-15 14:59:06 +0200 |
|---|---|---|
| committer | Ondrej Zajicek (work) <santiago@crfreenet.org> | 2016-09-15 14:59:06 +0200 |
| commit | 4adcb9df1bf551cc5fd1145c09af1843fdc4fe85 (patch) | |
| tree | 569aa0d159e63ea73b40a041300079f81538b34b /doc/bird.sgml | |
| parent | 2feaa6931bfe39eba696b33b0c8aac13d313b223 (diff) | |
KRT: Add kernel metric protocol option
Kernel routes with different metrics do not clash with each other,
therefore using dedicated metric value is a reliable way to avoid
overwriting routes from other sources (e.g. kernel device routes).
Although kernel route metric could already be set as a route attribute by
filters, that is not consistent with the way how Linux kernel handles
route metric - not just a route attribute, but a part of a route key.
Diffstat (limited to 'doc/bird.sgml')
| -rw-r--r-- | doc/bird.sgml | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/doc/bird.sgml b/doc/bird.sgml index 1af7f2c1..9bd7df86 100644 --- a/doc/bird.sgml +++ b/doc/bird.sgml @@ -2388,6 +2388,17 @@ limitations can be overcome using another routing table and the pipe protocol. protocol work with. Available only on systems supporting multiple routing tables. + <tag>metric <m/number/</tag> (Linux) + Use specified value as a kernel metric (priority) for all routes sent to + the kernel. When multiple routes for the same network are in the kernel + routing table, the Linux kernel chooses one with lower metric. Also, + routes with different metrics do not clash with each other, therefore + using dedicated metric value is a reliable way to avoid overwriting + routes from other sources (e.g. kernel device routes). Metric 0 has a + special meaning of undefined metric, in which either OS default is used, + or per-route metric can be set using <cf/krt_metric/ attribute. Default: + 0 (undefined). + <tag>graceful restart <m/switch/</tag> Participate in graceful restart recovery. If this option is enabled and a graceful restart recovery is active, the Kernel protocol will defer @@ -2420,9 +2431,11 @@ these attributes: route. See /etc/iproute2/rt_protos for common values. On BSD, it is based on STATIC and PROTOx flags. The attribute is read-only. - <tag>int <cf/krt_metric/</tag> + <tag>int <cf/krt_metric/</tag> (Linux) The kernel metric of the route. When multiple same routes are in a kernel routing table, the Linux kernel chooses one with lower metric. + Note that preferred way to set kernel metric is to use protocol option + <cf/metric/, unless per-route metric values are needed. <tag>ip <cf/krt_prefsrc/</tag> (Linux) The preferred source address. Used in source address selection for |