RWP and LHR NE40 routers are connected to each other using two E3 links. Suddenly one E3 link have no traffic in MRTG graph. After checking log buffer it come clear that the OSPF peer between LHR and RWP was down. At this time both interfaces were check and current state and line protocol was up on both RWP and LHR but still OSPF peer was down !!
%Sep 12 08:57:28 2006 Last neighbor down event: ROUTER ID: x.x.x.162 LOCAL ADDRESS: x.x.x.189 REMOTE ADDRESS: x.x.x.190 REASON: DeadInterval timer overtime
The system bucket size needs to be increased because due to media fluctuations there are many PPP and OSPF error packets which causes OSPF peer down event. After increasing the system bucket size the problem is resolved.
Use command "apply system-bucket slot-num protocol-num traffic-rate" , configure traffic rete to be 2K for PPP,and OSPF packets.