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New Member

Problems with OSPF

I have two routers at one place, which connect to other sites using serial links. one of them is Nortel make. we later added the other router, which is 7206VXR. Both run OSPF. The routers are on the same Ethernet LAN. 7206 is running IOS 12.1(5T)

in the local machines, if I configure the nortel router as default gateway, everyhting works fine.

If I configure the 7206VXR as the default gateway, everything works fine for 3-4 hours, and then communication to remote sites connectd to both routers stops.

The CPU utilisation at this point is 2-3%, both routers show all the links up, and also all the OSPF learned routes. But the communication doesn't take place.

We tried CEF but the symptoms remain same.

Can anybody guide me?

5 REPLIES
New Member

Re: Problems with OSPF

Hi.

So, let me see if I got it... You have a Nortel router and a 7206VXR on the same LAN, and these two routers connect to other sites using serial links?...

When communication stops what do you see on the routing tables of both routers?

Can you see on the 7206VXR the Nortel router as an OSPF neighbor?

Rgds.

NM

New Member

Re: Problems with OSPF

when communication stops, both the routers show the routes connected to them in therouting table

when the problem occurs, neither routers show the other as ospf neighbor

New Member

Re: Problems with OSPF

Hi.

When communication stops, the only routes the routers have in the routing table are directly connected networks only? Or do they have more routes learned via OSPF?

Rgds.

NM

New Member

Re: Problems with OSPF

Greetings

Few troubleshooting steps:

1. check that memory and cpu utilization is not much.

2. Don't use any cisco proprietry OSFP feature like totally stubby areas.

3.Check the IOS version and related bugs, u can use 12.2 (7a), this is a stable verison.

Anuj

New Member

Re: Problems with OSPF

Use the nortel rotuer as the gateway,

Open a telnet session to the Nortel poling the log:- log -fftwid -eOSPF. check the adjacent is still present 3-4 hours later.

You should see the adjancy loose conection, ping the Cisco from the command line and if possible from a PC terminated localy, i.e the same switch or hub.

Are these boxes on the same switch/hub? Once an adjancy has formed there are no reasons why after 3-4 hours OSPF should fail.

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