MPLS VPN design - RR in forwarding path?

Andriy Bilous andriy.bilous at
Fri Jan 2 10:16:26 UTC 2015

Given that you assign unique RD per PE, RR out of the forwarding path
provides you with a neat trick for fast convergence (and debugging
purposes) when CE has redundant paths to different PEs. Routes to those CEs
will be seen as different routes on RR.

On Wed, Dec 31, 2014 at 1:08 PM, Marcin Kurek <notify at>

> Hi everyone,
> I'm reading Randy's Zhang BGP Design and Implementation and I found
> following guidelines about designing RR-based MPLS VPN architecture:
> - Partition RRs
> - Move RRs out of the forwarding path
> - Use a high-end processor with maximum memory
> - Use peer groups
> - Tune RR routers for improved performance.
> Since the book is a bit outdated (2004) I'm curious if these rules still
> apply to modern SP networks.
> What would be the reasoning behind keeping RRs out of the forwarding path?
> Is it only a matter of performance and stability?
> Thanks,
> Marcin

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