OSPF routing issue

[dodusbacker]

Hi

Can somebody please help

I have cisco 3620  internet firewall router . the router cpu utilization becaus eof ospf process.

62   109947332   1642150      66953 96.84% 45.86% 44.08%   0 OSPF Router

Can you let me knwo what needs to be done to clear this issue

its really urgent

[Mark Rigby]

Without knowing the configuration and how many routes entries are in the 3620 it's hard to say. You could try resetting the OSPF process using "clear ip ospf process"

This will flush all OSPF routes but will result in a temporary loss of connectivity, how much of an impact this would have is hard to say without knowing the topology.

Regards

[rupam_chakra1983]

check whether the ospf neighborship with other device is fluctuating or not.

Check the interface for error or reset in show interface command.

[Giuseppe Larosa · Accepted solution]

Hello Dodu,

post

sh ip ospf database summary

sh ip ospf

the router can receive too many routes, of there are flapping routes and it is recalculating too many times

or an OSPF router-id war (duplicated router-id) is happening place in attachment the output of sh log

Hope to help

Giuseppe

[dodusbacker]

#show ip ospf
Routing Process "ospf 44" with ID 172.22.5.5
Supports only single TOS(TOS0) routes
Supports opaque LSA
It is an autonomous system boundary router
Redistributing External Routes from,
    connected, includes subnets in redistribution
    static, includes subnets in redistribution
SPF schedule delay 5 secs, Hold time between two SPFs 10 secs
Minimum LSA interval 5 secs. Minimum LSA arrival 1 secs
Number of external LSA 4677. Checksum Sum 0x92CEB6E
Number of opaque AS LSA 0. Checksum Sum 0x0
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 1. 1 normal 0 stub 0 nssa
External flood list length 0
    Area 100
        Number of interfaces in this area is 2
        Area has no authentication
        SPF algorithm executed 3 times
        Area ranges are
        Number of LSA 228. Checksum Sum 0x786793
        Number of opaque link LSA 0. Checksum Sum 0x0
        Number of DCbitless LSA 2
        Number of indication LSA 2
        Number of DoNotAge LSA 0
        Flood list length 0

There is no starnge logs concernng opsf its all about access list denying traffic

[Giuseppe Larosa]

Hello Dodu,

>> SPF algorithm executed 3 times
        Area ranges are
         Number of LSA 228.

SPF calculations is only 3, there are only 228 LSA, if there are no error messages regarding OSPF I would think of a possible IOS bug.

What IOS is running on the C3620?

Hope to help

Giuseppe

[dodusbacker]

Cisco Internetwork Operating System Software

IOS (tm) 3600 Software (C3620-I-M), Version 12.2(7), RELEASE SOFTWARE (fc1)

[dodusbacker]

it was working fine till date today only it caused issue