OSPF neighbors down

jolmo · ‎10-14-2007

Hi all

In a broadcast network (Ethernet) with several routers running OSPF with only one area (area 0) i'm often experimenting OSPF neighbors errors like:

%OSPF-5-ADJCHG: Process 1, Nbr 172.17.1.131 on Vlan1 from 2WAY to DOWN, Neighbor Down: Dead timer expired

%OSPF-5-ADJCHG: Process 1, Nbr 192.168.195.3 on Vlan1 from FULL to DOWN, Neighbor Down: Dead timer expired

%OSPF-5-ADJCHG: Process 1, Nbr 192.168.195.3 on Vlan1 from LOADING to FULL, Loading Done

The interfaces that connect routers are apparently OK with no errors or drops but OSPF failures are affecting almost every router in the LAN (8 routers running OSPF)

Where could it be the problem?

Thanks in advance

nambi_gct · ‎10-14-2007

Dead timer expires only of OSPF packets are lost or if the CPU of the sender is too busy.Can you please check the cpu utilisation of the problematic neighbors when this problem is seen.

jolmo · ‎10-14-2007

Thanks for your reply

I've checked it before and it is not a CPU issue

nambi_gct · ‎10-14-2007

Is this a periodic issue.What platform is this?

jolmo · ‎10-14-2007

It happens 4 or 5 times per day, but never at the same time.

The core routers are two layer 3 Catalyst 6500 running HSRP. They are connected by 1 Gbps link. This link looks right.