Re: bgp route advertisment , particularly aggregate/summary to

Aaron,

172.16.1.0/24
172.16.2.0/24
172.16.3.0/24

if these networks are not part of the IGP routes in the router from which
you wish to advertise an aggregate route you will have to create a null
route for the 172.0.0.0/8 network. You will not have to create a null
route as long as a longer prefix matches the aggregate exist in the Routing
Information Base (RIB).

A null route is not considered a static route.

http://www.cisco.com/en/US/docs/ios-xml/ios/iproute_bgp/command/bgp-a1.html#GUID-D8ACCE05-4ACE-42D5-8EC6-9607FF7FA9FD
http://www.cciecandidate.com/?p=97

Joe S.

On Sat, Mar 10, 2012 at 12:58 PM, Aaron <aaron1_at_gvtc.com> wrote:

> In a recent scenario I was using for my studies I was presented with the
> following..Please tell me how to do the following or link to where it is on
> doc cd.
>
>
>
> If R1 has in its igp table.
>
>
>
> 172.16.1.0/24
>
> 172.16.2.0/24
>
> 172.16.3.0/24
>
>
>
> And you need to send an aggregate of that as 172.0.0.0/8 to a IBGP
> neighbor
> how would you accomplish that? I don't think a static route is
> permissible.
> I don't think you can create additional interfaces on r1 either.
>
>
>
> If you can just verbalize to me a few ideas of how that is accomplished
> without some elaborate config then that's fine.like what are the moving
> parts?
>
>
>
> Is it possible to generate an aggregate based solely on the contents of the
> IGP table? I think I read that a subordinate part of a larger aggregate
> needs to be present in the igp table in order for the aggregate to be sent,
> but do I use "aggregate-address" ?....suppresmap? unsurprssmap? .neighbor
> statement to that certain neighbor?
>
>
>
> Aaron
>
>
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Received on Sun Mar 11 2012 - 21:49:30 ART