Re: Active BGP Probing and large AS-sets

[Lorenzo Colitti <lorenzo () ripe net>]

Randy Bush wrote:
> > Thus, to stop its announcement from being propagated by ASes 1, 2, and 
> > 3, an AS (say AS12654) might announce one of its prefixes with an 
> > AS-path of 12654 {1,2,3}.
>
> won't that prevent 12654's announcements from being received by, as
> opposed to propagated by, 1, 2, and 3?

More or less. Technically, unless sender-side loop detection is used, 
the routers in 1,2 and 3 will receive the announcement, but discard it 
because it contains the local AS. However, the path will not be one of 
the candidates for route selection, so it will probably not appear in 
the output of a query for the prefix, which amounts to much the same.


Regards,
Lorenzo

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