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why ospf routes refresh every 10 seconds

djsonicdh
Level 1
Level 1

Hi, i have a problem, the routers of ospf in the ip route table refresh every 10 seconds. The router has no dropped interfaces and no other log that indicates a particular problem. The ospf neighbors its ok.

System: WS-C6509 with Supervisor Engine 720

IOS version:12.2(33)SXJ10

Function of router: Backbone core, area 0 OSPF, has a couple of static routes with redistribution (redistribute static subnets)

9 Replies 9

Julio E. Moisa
VIP Alumni
VIP Alumni

Hi

Are The refreshed routes external? or are they learned by OSPF? If they are external  (E1 or E2) it could be a problem when the router who is injecting the routes or any redistribution problem like loops. 




>> Marcar como útil o contestado, si la respuesta resolvió la duda, esto ayuda a futuras consultas de otros miembros de la comunidad. <<

All routes (O E1, O E2, O IA) refresh every 10 seconds exactly (all of the same time).

Have you verified if this behavior is showed on the DR? Also you can use show ip ospf statistics detail  to determinate what happen.




>> Marcar como útil o contestado, si la respuesta resolvió la duda, esto ayuda a futuras consultas de otros miembros de la comunidad. <<

I have a lot of neighbors. Somes have point-to-point (no DR or BDR elected), and others have DR and BDR. I verefied in the DR neighbors, BDR neighbors and point-to-point neighbors and not have this problem.

EDIT: i cant upload files, but heres the show ip ospf statistics detail 

https://www.dropbox.com/s/eqxpk5vp20kwoep/log.log?dl=0

State
FULL/ -
FULL/ -
FULL/ -
FULL/ -
FULL/ -
FULL/ -
FULL/ -
FULL/DR
FULL/BDR
FULL/BDR
FULL/DR
FULL/DR
FULL/BDR
FULL/BDR
FULL/DR
FULL/BDR
FULL/DR
FULL/DR
FULL/BDR
FULL/ -
FULL/ -

It could be a flapping interface on your topology, have the OSPF timers modified or any change recently? Also try to configure ispf under the OSPF process to keep the changes into the each area. 

 Area 0: SPF algorithm executed 1379229 times



>> Marcar como útil o contestado, si la respuesta resolvió la duda, esto ayuda a futuras consultas de otros miembros de la comunidad. <<

check the router with router-id

161.131.1.216  there might be interface flapping on that router

Hello

Try to summarize where applicable and any areas that are not transit areas can be made stub areas so to decrease the amounts of lsa's from being refresh throughout the whole ospf domain

You can also enable incremental SPF (ISPF)in the router stanza - this can assist in negating a full spf tree recalculation when changes to type 1/2 lsa occurs, so Ospf only recalculates the part of the spf tree that needs to be done.

res
paul 


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Kind Regards
Paul

You may have duplicated range of IP addresses learned from multi location

Or duplicated loopback IP addresses

thanks,
this was my problem. duplicate ip addresses.