OSPF state inconsistency

[Przemyslaw Frasunek]

Dear all,

I'd like to reopen this thread. The problem still persists on BIRD 1.5.0.

> Dear all,
> 
> we are using BIRD 1.4.5 with OSPF on PPPoE access servers running FreeBSD 9.3
> and mpd 5.7. In order to achieve fail-over, each access server is listening on
> the same VLANs. The user connects to access server which first responds with
> PPPoE PADO.
> 
> Some of our subscribers need additional IPv4 prefix, which is routed via address
> assigned from pool. Such route is added by mpd on connect and deleted on
> disconnect or LCP timeout.
> 
> Unfortunately, we are experiencing OSPF state inconsistency between access
> servers, when user quickly disconnects from one node and connects to another.
> This is such example, which caused routing loop:
> 
> (on 193.138.118.89)
> # birdc show route for 46.21.220.80/28
> BIRD 1.4.5 ready.
> 46.21.220.80/28    via 193.138.118.90 on vlan0 [ospf1 13:08:12] * E2
> (10/10/10000) [193.138.118.90]
> 
> (on 193.138.118.90)
> # birdc show route for 46.21.220.80/28
> BIRD 1.4.5 ready.
> 
> 46.21.220.80/28    via 193.138.118.89 on vlan0 [ospf1 13:12:32] * E2
> (10/10/10000) [193.138.118.89]
> 
> Any ideas, how to fix it?
> 
> This is our bird.conf:
> 
> log syslog { remote, error, auth, fatal, bug };
> router id 193.138.118.90;
> 
> protocol kernel {
>         learn;
>         scan time 20;
>         export filter {
>                 if proto = "static_bgp" then reject;
>                 accept;
>         };
> }
> 
> protocol device {
>         scan time 10;
> }
> 
> protocol ospf {
>         preference 10;
>         import filter {
>                 accept;
>         };
>         export filter {
>                 if net.ip = 0.0.0.0 then reject;
>                 if source = RTS_STATIC then accept;
>                 if proto = "kernel1" then accept;
>                 if proto = "direct1" then accept;
>                 reject;
>         };
> 
>         area 0 {
>                 interface "vlan0" { };
>                 interface "vlan*" { stub; };
>                 interface "carp*" { stub; cost 1000; };
>         };
> }
> 
> protocol direct {
>         import filter {
>                 accept;
>         };
> };
>