From: Jim Devane (jdevane@nevadanap.com)
Date: Mon Jul 30 2007 - 20:55:17 ART
And really to that effect, you really need to do nothing extra when
configuring. The cluster-id will be the router-id and obviously
different.
Jim
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Scott Morris
Sent: Monday, July 30, 2007 4:43 AM
To: 'Toh Soon, Lim'
Cc: 'Group study'
Subject: RE: Potential Issue Configuring BGP Cluster ID
Correct, cluster-id isn't the only method of loop protection, just an
additional one per grouping!
So yes, for redundancy/backup, I would go for a different cluster ID per
RR.
Cheers,
Scott
_____
From: Toh Soon, Lim [mailto:tohsoon28@gmail.com]
Sent: Monday, July 30, 2007 5:26 AM
To: smorris@ipexpert.com
Cc: Group study
Subject: Re: Potential Issue Configuring BGP Cluster ID
Hi Scott,
Without the existence of the same cluster ID, I believe there's still
some
degree of loop prevention mechanism. e.g. the ORIGINATOR_ID?
If redundancy/backup is my primary design goal, should I go for
different
cluster ID, i.e. your point #1 ?
Thank you.
B.Rgds,
Lim TS
On 7/30/07, Scott Morris <smorris@ipexpert.com> wrote:
The existence of the same cluster ID will be seen as a BGP loop on any
received routes by the BGP process... So current best practice thinking
is
to make your cluster ID's deliberately different for this reason.
Otherwise, if the loop elimination is part of your design (e.g. not
really
backup), then by all means make them equal. That was the former best
practice concept. :)
HTH,
Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713,
JNCIE
#153, CISSP, et al.
CCSI/JNCI-M/JNCI-J
VP - Technical Training - IPexpert, Inc.
IPexpert Sr. Technical Instructor
A Cisco Learning Partner - We Accept Learning Credits!
Telephone: +1.810.326.1444
Fax: +1.810.454.0130
http://www.ipexpert.com
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Toh
Soon, Lim
Sent: Monday, July 30, 2007 12:50 AM
To: Group study
Subject: Potential Issue Configuring BGP Cluster ID
Hi All,
In a BGP route reflector design with dual RRs and all RR clients have
iBGP
sessions to both RRs, what's the implication if I don't configure both
RRs
in the same cluster (using the command "bgp cluster-id")?
If both RRs are configured to the same cluster ID, I notice the
following
issue:
If the BGP sessions between Client1-RR2 and Client2-RR1 are down at the
same
time, Client1 would not be able to learn the routes from Client2 and
vice
versa, due to the fact that the RRs will ignore each others' routes
after
seeing its own cluster ID in the CLUSTER_LIST.
Kindly shed some light on the above issue, and whether it's advisable to
configure the RRs in the same cluster.
Thank you.
B.Rgds,
Lim TS
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