summaryrefslogtreecommitdiff
path: root/doc
diff options
context:
space:
mode:
Diffstat (limited to 'doc')
-rw-r--r--doc/bird.sgml15
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