Hello all,
Thank you for insightful answers.
I was thinking mostly about the second scenario Chuck mentioned - where
some traffic naturally flows through the routers that are the RRs
because of MPLS LSP. Setting next-hop-self on all reflected routes would
be misconfiguration IMHO.
I am also aware of products like vMX or CSR1000v/XRv and the example
given by Saku makes me more interested in licensing/pricing options.
Regards,
Marcin
W dniu 2014-12-31 o 18:05, Chuck Anderson pisze:
On Wed, Dec 31, 2014 at 01:08:15PM +0100, Marcin Kurek wrote:
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Since the book is a bit outdated (2004) I'm curious if these rules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?
When they say "move RRs out of the forwarding path", they could mean
"don't force all traffic through the RRs". These are two different
things. Naive configurations could end up causing all VPN traffic to
go through the RRs (e.g. setting next-hop-self on all reflected
routes) whereas more correct configurations don't do that--but there
may be some traffic that natrually flows through the same routers that
are the RRs, via an MPLS LSP for example. That latter is fine in many
cases, the former is not. E.g. I would argue that a P-router can be
an RR if desired.
