To answer your original question:  Because even though confederation
sub-AS peerings are "eBGP" they operate much more like iBGP

1) the AD will be 200
2) the next-hop will not change as it will in a normal eBGP peering
3) certain BGP community values operate differently (no-export)

Because the next-hop will not change by default, it is sometimes
necessary to do it yourself.



On Fri, Apr 9, 2010 at 4:41 PM, Fabio Mendes <[email protected]> wrote:
> Could someone clarify a little question about BGP Confederations, please ?
> Well, here is the thing: Odom's CCIE R&S Cert Guide v4, page 412, figure
> 4-10 and example 10-14 have something I cannot grasp.
> If sub-ASes use eBGP rules to inform about updates between themselves, why
> should I use the neighbor next-hop-self command, between different sub-ASes
> ?
> The update flying inside AS 123 without change the NEXT_HOP received by
> R1(sub-AS 65001) and R3 (sub-AS 65023).
>
> Where is the catch ?
>
> --
>
> CCNA - Cisco Certified Network Associate
> CCNP - Cisco Certified Network Professional
>
> "A bird that you set free may be caught again, but a word that escapes your
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>
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-- 
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