Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Community Member

OSPF process goes down due to dead timer expiring

Helo all,

I am trying to figure out the reason why the following message appears in one of our router (router C) running OSPF:

%OSPF-5-ADJCHG: Process 200, Nbr 172.18.212.4 on ATM3/0/0.100 from FULL to DOWN, Neighbor Down: Dead timer expired

Let me explain the details:

ABR router A connected to Router B with one (1) POS link.(172.18.212.4)

ABR router A connected to Router C with one (1) DS-3 Wireless link. (172.17.223.12)

Here is a sample of the config:

Router A:

interface ATM3/0/0.100 point-to-point

ip address 172.17.223.12 255.255.255.0

ip verify unicast reverse-path

no ip redirects

no ip unreachables

no ip proxy-arp

no ip mroute-cache

pvc 1/1

!

!

interface POS3/1/0

description POS Link to Miramar Bldg.

ip address 172.18.212.4 255.255.255.0

ip verify unicast reverse-path

no ip redirects

no ip unreachables

no ip proxy-arp

rate-limit input access-group 100 8000 4470 4470 conform-action transmit exceed

-action drop

no ip mroute-cache

pos scramble-atm

pos flag c2 22

no cdp enable

router ospf 200

router-id 172.18.212.4

log-adjacency-changes

network 172.18.212.0 0.0.0.255 area 0

network 172.17.223.0 0.0.0.255 area 0

While debuging OSPF events the hello this error message appears.

The DS-3 link is shown as poit-to-point with a cost of 2. The POS is also shown a spoint-to-point with a cost of 1. This is normal since the POS has higher speed.

Please note that router B and C also connect each other trough a GE connection.

Since both links on router A are poitn-to-point which means they are NBMA, could this be the problem?

Any ideas will be appreciated,

Regards,

Carlos Roque

2 REPLIES
Gold

Re: OSPF process goes down due to dead timer expiring

Dead timer expired means the router hasn't received a hello within the dead time, so it assumes the neighbor has failed. It sounds like you are losing connectivity for some reason for some period of time.

I would check any console logs for interface events, and then I would do a debug ip ospf nei, or possibly even a debug ip ospf packet, to see if I could figure out when the hello's are being dropped, and what's going on.

What is the cpu utilization like? Could we be dropping hello's because of high cpu util? Is the interface dropping a lot of packets?

:-)

Russ.W

Community Member

Re: OSPF process goes down due to dead timer expiring

Correct,

I checked both routers logs and found out the link has been flapping all day long.

I will have to verify the wireless link to see what is the problem.

Thanks for your response...

Carlos Roque

189
Views
0
Helpful
2
Replies
CreatePlease to create content