Amazing Problem with default Route injection in OSPF

Unanswered Question
May 18th, 2007

We have an amazing problem going on in our network . Our gateway router is a cisco 7200 series router, below it are many 3600 routers. We have two upstream providers . One week back suddenly it so happened one of our maintainenace staff pulled out the power cord of the gateway 7200 router accidentally. After the router rebooted suddenly we happened to face an amazing problem. The default route was not propagated to routers below the 7200 routers . We had to add manually static routes in every routers. We then removed the default-information originate always command in gateway router and shifted the command to one of the 3600 routers below the 7200 router and also pointed a default route to our gateway router. Now the routers below are starting to receive the propagated routes. We also tried to reboot the Gateway 7200 router in a proper fashion and reverted back the default information originate command to the gateway but again the same problem is continuing. We have reverted to 3600 router as a solution but the CPU usage of 3600 router is turning extremely high. Need a Solution immediately

I have this problem too.
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Harold Ritter Fri, 05/18/2007 - 04:40

To troubleshoot further, you would need to find out why the default route is either not advertised by the 7200 or not used by the other routers. For us to help, you would need to attach a "sh ip ospf da ext 0.0.0.0" from the 7200 and one 3600, while the 7200 is configured to originate the default route.

Hope this helps,

openboy_basanta Fri, 05/18/2007 - 05:28

cisco 7206 "sh ip ospf da ext 0.0.0.0" results

OSPF Router with ID (202.52.227.254) (Process ID 1)

Type-5 AS External Link States

Routing Bit Set on this LSA

LS age: 1506

Options: (No TOS-capability, DC)

LS Type: AS External Link

Link State ID: 0.0.0.0 (External Network Number )

Advertising Router: 202.52.227.129

LS Seq Number: 80000003

Checksum: 0x301C

Length: 36

Network Mask: /0

Metric Type: 2 (Larger than any link state path)

TOS: 0

Metric: 1

Forward Address: 0.0.0.0

External Route Tag: 1

cisco 3600 "sh ip ospf da ext 0.0.0.0" results

OSPF Router with ID (202.52.227.129) (Process ID 1)

Type-5 AS External Link States

LS age: 1751

Options: (No TOS-capability, DC)

LS Type: AS External Link

Link State ID: 0.0.0.0 (External Network Number )

Advertising Router: 202.52.227.129

LS Seq Number: 80000003

Checksum: 0x301C

Length: 36

Network Mask: /0

Metric Type: 2 (Larger than any link state path)

TOS: 0

Metric: 1

Forward Address: 0.0.0.0

External Route Tag: 1

Right now "default information originate always" command is in the 3600 router, and the router has static route to 7200 router, 7200 router has it towards our upstream provider

Thanks

royalblues Fri, 05/18/2007 - 05:41

The 7200 is showing the 3600 as advertising the default route.

Have you tried clearing the OSPF process

Narayan

openboy_basanta Fri, 05/18/2007 - 19:37

I have cleared ospf process earlier, still isnt working. I even cleared ospf process in routers below. The amazing thing is how it is working when the command is issued in 3600 router but doesnt work when issued in the gateway 7206. Debugging increases the load of CPU of router and we will get heavy complain of latency for sure.

Any more debugging ideas, shall I post Router configurations ????

rajivrajan1 Fri, 05/18/2007 - 20:36

hi,

Y don't you revert the configuration to 7200 (Default info originate) and try to get some debugs .. when traffic is low or noload.

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