Directly connected interface redistribution problem

28 Sep 2011

      I am using a config a little like the one below to import routes directed
at interfaces into bird (by which I mean a /32 routed out of an interface
with a static route) and then redistribute them into OSPF. The configuration
in general works.

If I
a) start bird (assume an empty routing table)
b) pause for several seconds / minutes
c) add the interface
d) add the /32 static route to the interface

then all is well.

If I omit step (b) above, then the route appears to get imported into
the evrospf protocol (i.e. 'show protocols all evrospf' shows the same
thing) but it never makes it to the OSPF peer (Quagga in this case).
A "restart evrospf" fixes it.

It /seems/ that if kernel routes are added whilst bird is starting
up (or perhaps whilst the adjacency is being formed), then those
changes are lost.

Any ideas on this, or how to debug it further? I suppose I can
work around it with a sleep(), but it is a bit arbitrary as I have
no idea how long to sleep for.

-- 
Alex Bligh

# Import kernel routes. These come in with RTS_INHERIT
protocol kernel evrkernel {
        persist;                # Don't remove routes on bird shutdown
        scan time 10;           # Scan kernel routing table every 20 seconds
        import all;
        export all;
        learn;                  # Learn all alien routes from the kernel
}

# This pseudo-protocol watches all interface up/down events.
protocol device {
        scan time 10;           # Scan interfaces every 10 seconds
}

# Import all directly connected routes. These come in with RTS_DEVICE
protocol direct evrdirect {
         interface "-evrr-000000", "evrr-*";
         export all;
}

protocol ospf evrospf {
        area 0.0.0.0 {
                interface "evrr-000000" {
                        cost 20;
                        priority 1;
                };
        };
        export filter {
               # RTS_INHERIT means routes from the kernel
               if net = 0.0.0.0/0 then reject;
               if (source = RTS_INHERIT) || (source = RTS_DEVICE) then {
                      accept;
               }
               reject;
        };
}