OSPF Dead Timers Expiring

gavin.mckee · ‎12-10-2007

Hi,

I am being plagued by OSPF adjacency drops in my network and there seems to be no reason why these occur, other than the dead timer expiring. The timers have been tweaked and I include my configuration + the syslog message that appears when I loss the adjacency. There is no extra load on the interfaces that could cause congestion. Any help well rated !!

router ospf 100

router-id 10.199.101.101

log-adjacency-changes

auto-cost reference-bandwidth 10000

timers throttle spf 10 100 5000

timers throttle lsa all 10 100 5000

network 10.199.101.101 0.0.0.0 area 0

network 192.168.70.109 0.0.0.0 area 0

network 192.168.70.198 0.0.0.0 area 0

network 192.168.70.205 0.0.0.0 area 0

000134: *Dec 9 03:07:44 GMT: %OSPF-5-ADJCHG: Process 100, Nbr 10.199.2.2 on GigabitEthernet0/0 from FULL to DOWN, Neighbor Down: Dead timer expired

000135: *Dec 9 03:07:49 GMT: %OSPF-5-ADJCHG: Process 100, Nbr 10.199.2.2 on GigabitEthernet0/0 from LOADING to FULL, Loading Done

Thanks

Gavin

smothuku · ‎12-10-2007

Hi Gavin ,

What is connected on G0/0 and 10.199.2.2 belongs to which device.

Can you paste "show ip ospf nei" , "sh int g0/0" "show ip route" output.

And we can see what is happening exatcly using "debug ip ospf adj" command.

If possible few more sys log messages.

Are u getting any messages on the device connected to G0/0.

Thanks,

satish

gavin.mckee · ‎12-10-2007

Hi Satish

Here is the show ip ospf neigh:

10.199.202.202 0 FULL/ - 00:00:30 192.168.70.110 Serial3/0

10.199.200.200 1 FULL/DR 00:00:32 192.168.70.206 GigabitEthernet0/1

10.199.2.2 255 FULL/DR 852 msec 192.168.70.197 GigabitEthernet0/0

core-rtr2#show interface gi0/0

GigabitEthernet0/0 is up, line protocol is up

Hardware is BCM1125 Internal MAC, address is 001b.53d8.f030 (bia 001b.53d8.f030)

Description: *** L3 connection to Core-Sw2 ***

Internet address is 192.168.70.198/30

MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,

reliability 255/255, txload 1/255, rxload 1/255

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 1000Mb/s, link type is autonegotiation, media type is SX

output flow-control is XON, input flow-control is XON

Carrier delay is 0 msec

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:00, output 00:00:00, output hang never

Last clearing of "show interface" counters never

Input queue: 0/75/1/138 (size/max/drops/flushes); Total output drops: 0

Queueing strategy: fifo

Output queue: 0/40 (size/max)

30 second input rate 5260000 bits/sec, 1432 packets/sec

30 second output rate 7751000 bits/sec, 1372 packets/sec

783061295 packets input, 4153364948 bytes, 0 no buffer

Received 1 broadcasts, 0 runts, 0 giants, 1 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog, 9407712 multicast, 0 pause input

0 input packets with dribble condition detected

1272598932 packets output, 2237666961 bytes, 0 underruns

4 output errors, 0 collisions, 3 interface resets

0 babbles, 0 late collision, 0 deferred

4 lost carrier, 0 no carrier, 0 pause output

0 output buffer failures, 0 output buffers swapped out

The stange thing here is that the interface does not flap, the network is in fact stable. The only syslog I get relates to the dead timer expiring. This output is from a Cisco 3825 the other end is a 6506E with SUP720.

As you can see the results are very strange!

Thanks

Gavin

smothuku · ‎12-10-2007

Hi Gavin ,

Run "debug is opsf adj" on both the devices and paste the output.

If you check below lines taken from show ip ospf nei

10.199.200.200 1 FULL/DR 00:00:32 192.168.70.206 GigabitEthernet0/1

10.199.2.2 255 FULL/DR 852 msec 192.168.70.197 GigabitEthernet0/0

10.199.200.200 dead timer is 32 milli sec where as for 10.199.2.2 it is 852 msec.

Why is the difference in values of dead timer ?

This value must be the same for all routers and access servers on a specific network.

Have you configured any dead timer on the interfaces on both ends ?

Thanks,

satish