From: Bob Sinclair (bsin@cox.net)
Date: Fri Dec 05 2003 - 11:55:04 GMT-3
Howard,
My reading of the portion of RFC 3065 quoted below would seem to be in
accord with the Halabi's reference. Am I misreading it?
quote>
It shall be legal for a BGP speaker to advertise an unchanged
NEXT_HOP and MULTI_EXIT_DISCRIMINATOR (MED) attribute to peers in a
neighboring AS within the same confederation. In addition, the
restriction against sending the LOCAL_PREFERENCE attribute to peers
in a neighboring AS within the same confederation is removed. Path
selection criteria for information received from members inside a
confederation MUST follow the same rules used for information
received from members inside the same autonomous system, as specified
in [1].
end quote.
Thanks!
-Bob Sinclair
CCIE #10427, CISSP, MCSE
bsinclair@netmasterclass.net
----- Original Message -----
From: "Howard C. Berkowitz" <hcb@gettcomm.com>
To: <ccielab@groupstudy.com>
Sent: Friday, December 05, 2003 9:10 AM
Subject: Re: The bgp confederation peers as-number [... as-number] command
> At 10:29 PM -0500 12/4/03, Bob Sinclair wrote:
> >CCIE2B,
> >
> >Doyle V2 is the only reference I can find that explicitly says that you
only
> >have to include sub-AS's with with you actually peer (page 289). If a
> >particular router does not peer with a router in another sub-AS, then it
> >does not need to list that sub-AS in the confederation peer statement.
This
> >makes sense given Halabi's explanation of this command:
> >
> >quote from page 421>
> >
> >RTG uses the router command bgp confederation peers 65060 to preserve all
> >the attributes, such as local preference and next hop when traversing the
> >EBGP session to AS 65060
> >
> >end quote.
>
> I'm a little confused by that quote. next_hop is a mandatory
> attribute, but local preference shouldn't go outside the sub-AS.
> Even between sub-AS, you should be using MED or other preference
> setting mechanisms such as communities with route maps.
>
> >
> >In other words, the command qualifies a peer statement. If there is no
peer
> >statement to a given sub-AS, then there is no need to qualify it.
> >
> >Hope that helps,
> >
> >-Bob Sinclair
> > CCIE #10427, CISSP, MCSE
> > bsinclair@netmasterclass.net
> >
> >
> >----- Original Message -----
> >From: "ccie2be" <ccie2be@nyc.rr.com>
> >To: "kasturi cisco" <kasturi_cisco@hotmail.com>; <ccielab@groupstudy.com>
> >Sent: Wednesday, December 03, 2003 8:50 AM
> >Subject: Re: The bgp confederation peers as-number [... as-number]
command
> >
> >
> >> Hi Kasturi,
> >>
> >> Thanks for your response. I think, however, you didn't quite
understand
> >what
> >> I was asking.
> >>
> >> What you said is correct but doesn't address the question I had. My
> >question
> >> was which sub AS's should be specified with this command. There are 2
> >> possible choices: List all sub AS's in the confed or list just those
sub
> >AS's
> >> to which the router is peering.
> >> ----- Original Message -----
> >> From: kasturi cisco
> >> To: ccie2be@nyc.rr.com ; ccielab@groupstudy.com
> >> Sent: Wednesday, December 03, 2003 8:08 AM
> >> Subject: RE: The bgp confederation peers as-number [... as-number]
> >command
> >>
> >>
> >> Hi,
> >>
> >> The way i have used it and seen it being used is follows:
> >>
> >> If there is a Confed with multiple Sub-As then the confed peers is
for
> >> routers which have another Sub As peer. Routers within confed-sub-As
> >and/or
> >> routers with no peering to another sub AS need not use the command.
> >>
> > > As always correct me if needed.
>
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