Filtering static routes in OSPF

[SGingolaski]

Greetings All -

Our routers and L3 switches are set up to automatically redistribute static routes into OSPF. However, a request has come down for us to add a new static route but not to redistribute it throughout the OSPF areas.

With EIGRP this was not a problem, but since the command "distribute-list out" works only on the routes being redistributed by the Autonomous System Boundary Routers(ASBRs) into OSPF, I am not sure how to stop the redistribution. The concern is that if this route propagates throughout the network, it will cause the usual list of undesirable effects.

Is this something that can be handled by a RouteMap or is there a better way to do this?

Thanks,

[Richard Burts]

It seems to me that a distribute list which denies the static route that you do not want to advertise and permits other static routes and is applied on the OSPF router where the static is redistributed is a workable solution. Why do you think that this would not work?

HTH

Rick

[SGingolaski]

Thank you for the reply.

My reason for not using the distribute-list out command was from my understanding of the below passage from a Cisco white page.

"The command distribute-list out works only on the routes being redistributed by the Autonomous System Boundary Routers(ASBRs) into OSPF. It can be applied to external type 2 and external type 1 routes, but not to intra-area and interarea routes."

My understanding of this was that the distribute-list out command would only keep the routes from being redistibuted outside the AS but would still be distributed throughout the OSPF areas.

Am I not understanding this correctly?

Thanks,

[Harold Ritter]

The command distribute-list applies to routes being redistributed in OSPF from a dynamic routing protocols or static routes.

Hope this helps,

[Harold Ritter]

Why not just use a route-map as you redistribute in OSPF as follow:

router ospf 1

redistribute static subnets route-map static2ospf

route-map static2ospf deny 10

match tag 999

route-map static2ospf permit 20

and the new static routes would be as follow:

ip route 192.168.1.0 255.255.255.0 192.168.2.1 tag 999

Hops this helps,

[SGingolaski]

That is very slick and seems to have worked very well. Thank you for all the help.

Thanks