[c-nsp] MBGP for Multicast with VRF-Lite

[Phil Mayers]

On 03/05/11 12:49, Arie Vayner (avayner) wrote:
> James,
>
> Why do you need to advertise multicast routes over BGP?

We had to do this a while back to comply with upstream policies. They 
were running multicast AF, and if we didn't advertise our unicast 
prefixes into the multicast AF as well, RPF would always fail.

IIRC this was some limitation of the IOS version they were running on 
their GSRs, but it was a long time ago.

Point being: it's

>
> I multicast, usually, you need to advertise the sources (regular
> unicast...) to be reachable through the path where multicast is flowing
> (to make RPF work).

Isn't that what he's asking for?

The problem is, you can't do this:

router bgp xxx
   address-family ipv4 unicast vrf XXX
     neighbor <upstream> remote-as zzz
     neighbor <upstream> activate

   address-family ipv4 multicast vrf XXX
     neighbor <upstream> activate
     ! pin up your network blocks
     network 192.0.2.0 255.255.255.0