Static: Support for multiple routes with the same network

Add support for proper handling of multiple routes with the same network
to the static protocol. Routes are distinguished by internal index, which
is assigned automatically (sequentially for routes within each network).
Having different route preference or igp_metric attribute is optional.

1 files changed, 9 insertions, 2 deletions

diff --git a/doc/bird.sgml b/doc/bird.sgml
index 9d1047a8..05216c4a 100644
--- a/doc/bird.sgml
+++ b/doc/bird.sgml
@@ -4938,8 +4938,15 @@ default route to prevent routing loops).
 
 <p>There are three classes of definitions in Static protocol configuration --
 global options, static route definitions, and per-route options. Usually, the
-definition of the protocol contains mainly a list of static routes.
-Static routes have no specific attributes.
+definition of the protocol contains mainly a list of static routes. Static
+routes have no specific attributes, but <ref id="rta-igp-metric" name="igp_metric">
+attribute is used to compare static routes with the same preference.
+
+<p>The list of static routes may contain multiple routes for the same network
+(usually, but not necessary, distinquished by <cf/preference/ or <cf/igp_metric/),
+but only routes of the same network type are allowed, as the static protocol
+has just one channel. E.g., to have both IPv4 and IPv6 static routes, define two
+static protocols, each with appropriate routes and channel.
 
 <p>Global options: