[c-nsp] Number of route reflectors, best practice?

[Matt Addison]

On Sun, Jul 24, 2011 at 10:10, Mark Tinka <mtinka at globaltransit.net> wrote:
> We generally prefer the Cisco 7201 as a route reflector
> (which would send us to the ASR1001 as an upgrade path,
> despite the 512,000 FIB entry support), but we wanted to
> support the MCAST-VPN AFI (for LSM) which only the Juniper
> supports today. So it was a case of:

The ASR1001 supports the (poorly advertised and not-at-all documented
it seems) BGP selective download feature- which can filter routes from
BGP to the RIB.

route-map bgp-to-rib deny 10
!

router bgp 64512
 address family ipv4 unicast
   table-map bgp-to-rib filter
!

This should prevent any routes moving from BGP to the RIB (suitable
for a network using next-hop-self and all next-hops are visible in the
IGP). If you don't run next-hop-self on all your boundary routers
you'd need to find some way to get those routes needed for next hop
resolution into the table (Cisco recommends tagging them with a
community, and using this to allow those particular routes to move
from BGP to RIB).

~Matt