Re: BGP distribute list

The standard way of doing BGP filtering is per neighbor/group/template.
Sure, unless there are any restrictions, you can do it in the routing
process, but then how can you be certain that the behavior will be what you
expect? You'd need to test it, and that's not a good thing to do in the lab.

If there are no restrictions or guidelines, the usual way of doing filtering
is NLRI format and per neighbor filtering.

On Fri, Apr 17, 2009 at 4:26 PM, Ivan <ivanzghr_at_gmail.com> wrote:

> Hello,
>
> Scenario:
>
> R1 ------------ R2
> | |
> | |
> | |
> R4-------------R3
>
> each router is in different AS. If you want to filter one prefix on R2 that
> originated in R1's AS with distribute list, is it correct to do it globally
> under router bgp:
>
> Ex 1:
> router bgp 200
> distribute-list 1 in
>
> or you must put it on every external neighbor:
>
> Ex 2:
> router bgp 200
> neighbor R1 remote-as 1
> neighbor R3 remote-as 3
> neighbor R1 distribute-list 1 in
> neighbor R2 distribute-list 1 in
>
> If the task asks to filter prefix from R1, it means filter from all
> possible
> sources (all external peers). So, in that case is it OK to put like in ex.
> 1
> or do you have to do it neighbor by neighbor like Ex 2 ?
> Ex 1 works fine.
>
>
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-- 
Pavel Bykov
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