[Xorp-users] Re: help establishing OSPF adjacencies

[Pavlin Radoslavov]

> > Then the routers are not seeing each others packets.
> 
> 
> Yep.  I suspect that the routers are not joining the multicast group
> properly.  tcpdump shows :
> 
> 12:58:16.282879 IP planetlab4.csail.mit.edu > OSPF-ALL.MCAST.NET:
> OSPFv2, Hello (1), length: 44
> 
> and
> 
> 12:55:03.896093 IP planetlab5.csail.mit.edu > OSPF-ALL.MCAST.NET:
> OSPFv2, Hello (1), length: 44
> 
> but, for some reason, they aren't hearing each other's hellos.  I
> suspect it's a problem with multicast.  I see the attemt to join the
> multicast group in the XORP debug:
> 
> [ 1068  +430 xrl_io.cc join_multicast_group ] Join Interface eth0 Vif
> eth0 mcast 224.0.0.5
> 
> But I suspect that it is not succeeding for some reason.

What is the output of "netstat -g"? It will show the multicast
groups joined on each interface.
If the group is joined, then I suspect there are some firewall
filters on the receiver side that prevent the multicast packets from
reaching the receiver.

Pavlin