Re: Query related to Auto Discovery as in draft-ietf-l3vpn-2547bis-mcast-07.txt

[Yakov Rekhter <[e-mail]>]

Subinoy,

> Thanks for answer. I still have confision about the exact process.
> 
> If local policy states to discard route if RT does not match Import
> then what happen if new VPN support is added to a PE? How does it
> comes to know all routes for that VPN? 

>From Section 4.3.2 of rfc4364:

   A PE router, UNLESS it is a route reflector (see Section 4.3.3) or an
   Autonomous System Border Router (ASBR) for an inter-provider VPN (see
   Section 10), should not install a VPN-IPv4 route unless it has at
   least one VRF with an Import Target identical to one of the route's
   Route Target attributes.  Inbound filtering should be used to cause
   such routes to be discarded.  If a new Import Target is later added
   to one of the PE's VRFs (a "VPN Join" operation), it must then
   acquire the routes it may previously have discarded.  This can be
   done using the refresh mechanism described in [BGP-RFSH].  The
   outbound route filtering mechanism of [BGP-ORF] can also be used to
   advantage to make the filtering more dynamic.

To which I may add that one may use RT Constrain (rfc4684) instead
of [BGP-ORF], as RT Constrain is more useful that [BGP-ORF].

> Should all other PEs send
> I-PMSI A-D Route, S-PMSI A-D Route, Source Active A-D Route,
> C-Multicast Route to that PE?

See the above.

Yakov.