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TOPIC: OSPFand BGP on same router

OSPFand BGP on same router 4 years 9 months ago #37746

  • steveb13
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I'm hoping someone has come across this before and has the solution. I have a scenario with a Cisco 6506 and a 7206. The 6506 is running BGP and peers with our data center router. The 7206 is a stub router off the 6506 and is used as an edge router for customer T1 circuits. I want to use OSPF between the routers to exchange connected and static routes. The problem I have is that static BGP null routes on the 6506 are overriding the OSPF routes being received from the 7206.


The 6506 is advertising a class C network to our data center. The 6506 does not utilize the network. It is only used on the 7206 for customer T1 circuits and is carved up into /29 subnets. So the 6506 has a static route: ip route null 0. Today the routing is accomplished with static routes on the 6506 for the networks on the 7206. Using OSPF the 7206 advertises /29 links back to the 6506, but when I withdraw one of the /29 static routes from the 6506, the /24 null route takes precedence over the more specific /29 routes and the traffic is black-holed on the 6506.

So my question is - how can I get the OSPF routes to look preferable to the /24 null route on the 6506?

Thanks for the help and let me know if my example is not clear.
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Re: OSPFand BGP on same router 4 years 8 months ago #37817

  • Chojin
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You're saying a /24 route wins over a /29 route?!

Are you sure the /29 is displayed when using the command "show ip route"?
Even though the AD of a static route is 1 and OSPF has 110, it should take the 110 because its more specific.

What types of routes do you get within OSPF when advertising the /29's? Are those advertised by a redistribute static? network x.x.x.x? Auto-summary enabled?

This one is a nice one to break :). One thing is for sure... we'll crack this puppy :)
CCNA / CCNP / CCNA - Security / CCIP / Prince2 / Checkpoint CCSA
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