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New Member

BGP routes

A Chairde,

I have a 7609 Core Router connected to 10 + networks in a hub spoke configuration, and use BGP as routing protocol.

Have setup each network with seperate AS, but am getting complaints that the routers in AS have all routes from other networks in their routing tables, they are connected to Cisco only.

How can I setup config that only routes 7609 sends out are for its AS only, and not all other ASs ??????

2 ACCEPTED SOLUTIONS

Accepted Solutions
Hall of Fame Super Silver

Re: BGP routes

Ed

I think I do not understand well what you are attempting to accomplish. The intent of BGP is to learn routes from one neighbor and advertise them to other neighbors, especially when the neighbors are in other ASes (which is EBGP). But it seems that you want to run BGP but not have it advertise other AS routes.

But the immediate answer to your question is that if you do not want the 7609 to advertise some of the routes that it has learned then you must apply a filter to the routing updates. There are multiple types of filters that could be used. Probably the optimum filter for your purposes would be an AS filter.

HTH

Rick

Bronze

Re: BGP routes

You can configure route maps to do this.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008047915d.shtml

You can specificy which routes should be advertised to each peer.

Daniel

4 REPLIES
Hall of Fame Super Silver

Re: BGP routes

Ed

I think I do not understand well what you are attempting to accomplish. The intent of BGP is to learn routes from one neighbor and advertise them to other neighbors, especially when the neighbors are in other ASes (which is EBGP). But it seems that you want to run BGP but not have it advertise other AS routes.

But the immediate answer to your question is that if you do not want the 7609 to advertise some of the routes that it has learned then you must apply a filter to the routing updates. There are multiple types of filters that could be used. Probably the optimum filter for your purposes would be an AS filter.

HTH

Rick

New Member

Re: BGP routes

Are the ASes that you are connected to private or public? If they are all private you can use the remove private as command for each neighbor. This will prevent you from advertising the private ASes of each connection to eachother. If the ASes are public, then you can use an as filter like rburts suggests. You could even do somehting like a route-map localonly which would only allow you to advertise locally generated routes to each of your connection.

New Member

Re: BGP routes

Jim, RBurts,

Thanks for the help on this, The other nodes in the networks are not Cisco , and do not support BGP Filtering, this is why I am focussing on the 7609.

Slan / Ed

Bronze

Re: BGP routes

You can configure route maps to do this.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008047915d.shtml

You can specificy which routes should be advertised to each peer.

Daniel

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