Strange OSPF issue


(Esuyawkal S) #1

I have a network Core, Distribution, Acess design, from the core we have 4 remote Campues Distribution Switches connected via OSPF.
Sudden Restart from the Remote campus cause one of the distribution switches not to be active for OSPF

Let me make it clear
Before Restart
-OSPF was working from the Dist to the core

After Restart
-With the same or working Configuration of OSPF only one remote Campus not working for OSPF
-the core and the remaining 3 sites working fine with OSPF
-for the Distribution Switch which refuses OSPF, I configure EIGRP redistribute with the Core OSPF service is working now
Distribution Switch Not working info

License Information for ‘WS-X45-SUP8-E’
License Level: entservices Type: Permanent Right-To-Use
Next reboot license Level: entservices

cisco WS-C4507R+E (P5040) processor (revision 2) with 4194304K bytes of physical memory.
Processor board ID FXS2015Q0NY
P5040 CPU at 2.2GHz, Supervisor 8-E
Last reset from PowerUp
498 Virtual Ethernet interfaces
192 Gigabit Ethernet interfaces
16 Ten Gigabit Ethernet interfaces
511K bytes of non-volatile configuration memory.
Core switch info
cisco WS-C6504-E (R7000) processor (revision 2.0) with 1040384K/8192K bytes of memory.
Processor board ID FOX1501G656
SR71000 CPU at 600Mhz, Implementation 1284, Rev 1.2, 512KB L2 Cache
Last reset from s/w reset
8 Virtual Ethernet interfaces
6 Gigabit Ethernet interfaces
36 Ten Gigabit Ethernet interfaces
1917K bytes of non-volatile configuration memory.
working Distrbution info

cisco WS-C4506-E (MPC8548) processor (revision 6) with 1048576K bytes of memory.
Processor board ID FOX1503GNF4
MPC8548 CPU at 1.33GHz, Supervisor 6-E
Last reset from PowerUp
500 Virtual Ethernet interfaces
100 Gigabit Ethernet interfaces
2 Ten Gigabit Ethernet interfaces
511K bytes of non-volatile configuration memory.


(Lazaros Agapides) #2

Hello Esuyawkal

It is vital to find out why the distribution switch is not creating a neighbor relationship. I know this is a production network and troubleshooting may be awkward, and you may need to schedule some downtime for this. However, I would suggest the following:

When configuring the core to the distribution switch connection, attempt to configure OSPF correctly and then do some debugs on both ends. See if OSPF packets are actually arriving at both ends, and what the results are.

Secondly, a less disruptive troubleshooting process is to bring in another OSPF enabled router/switch at the distribution switch’s campus location. Enable OSPF on one interface, and do the same with the distribution switch (be careful what subnets you will be advertising!! Don’t use any ones that are on your network or routing will fail on your whole network). Connect them and see if you can successfully create OSPF neighbours. If not, then you have more info to go on with troubleshooting. If it works, then maybe you have to look at the link between the core and distribution in order to determine if packets are indeed being exchanged.

I believe this will give you a much clearer picture as to what is going on. This will also allow Cisco TAC engineers to more readily help you in troubleshooting the problem. Let us know of your progress!!

I hope this has been helpful!

Laz