From: Greg Schmitt (GSchmitt@xxxxxxxxxxxxx)
Date: Wed Jun 14 2000 - 22:45:28 GMT-3
Michael,
Correct. Think of it this way. You have a large AS. You don't want to have
to make a full mesh between all members (a requirement if using IBGP). So...
you decide to use BGP confederations (as opposed to route reflectors). You
split the large AS into sub AS's (careful how you use capitalization and
spell check here ;-)
Members inside each sub AS are joined with IBGP statements. The sub AS's are
joined, at the boundaries, with EBGP statements and by the bgp confed peers
statement. The bgp confed id statement (on each member of the confederation)
joins all sub AS's together so that they appear to be one AS to external
neighbors (identified with the AS number used in the confed id statement).
Note: The external neighbors of the confederation use the AS number of the
confed id statement in their remote as statement.
Does this make sense? It's getting late, and I've been up for a while now!
;-)
Cheers,
Greg Schmitt
Internetwork Solutions Engineer
ThruPoint, Inc. (formerly Total Network Solutions)
Current: 703-394-4577 (Client Location)
Voice: 410-349-9772
Cell: 443-822-5183
Pager: 888-773-0423 or pager.gschmitt@thrupoint.net
e-mail: GSchmitt@thrupoint.net
-----Original Message-----
From: Michael Needham [mailto:mineedha@cisco.com]
Sent: Wednesday, June 14, 2000 8:19 PM
To: Greg Schmitt
Cc: CCIELAB@groupstudy.com
Subject: Re: BGP CONFEDERATIONS Question
So then the connections within the Confederation are really considered
EBGPbetween each confederation AS? Hence the need for EBGP multihop if I
use an address other than the local connection between two members of
the confereration with differnt peer IDs???
Greg Schmitt wrote:
>
> Michael,
>
> Answers (hopefully correct) in line.
>
> Cheers,
>
> Greg Schmitt
>
> Internetwork Solutions Engineer
> ThruPoint, Inc. (formerly Total Network Solutions)
> Current: 703-394-4577 (Client Location)
> Voice: 410-349-9772
> Cell: 443-822-5183
> Pager: 888-773-0423 or pager.gschmitt@thrupoint.net
> e-mail: GSchmitt@thrupoint.net
>
> -----Original Message-----
> From: Michael Needham [mailto:mineedha@cisco.com]
> Sent: Wednesday, June 14, 2000 4:48 PM
> To: CCIELAB@groupstudy.com
> Subject: BGP CONFEDERATIONS Question
>
> In a confederation can I still use update-source between two different
> portions of the confederated network. Ie between 5555 to 4444 neigbors
> with a confed of 6?
>
> ===>Yes, they are separate autonomous systems (EBGP).
>
> If I continue to use a loopback as a neighbor address do I need EBGP
> multihop between to two AS's within the confed. to permit
connectivity?
>
> ===>Yes, they are separate autonomous systems (EBGP).
>
> Does the next-hop commands still relative within the confed?
>
> ===>If you are talking about between 5555 and 4444, then probably not.
> Usually the different ASs are directly connected, and you have a
default
> route pointing to the loopback address.
>
> Finally, if a router is part of a confederation and has no other
> connections other to a member of it's "native" conferedation, do you
> still need the confederation peer ID command???
>
> ===>Yes. All routers involved in a confederation must have the peer
> statement.
>
> I'm doing a rather complex LAb (self invented) and having issues with
> such... Thanks
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