RE: Distribution of VPN routing info. to P routers

["Vishal Sharma" <v.sharma at ieee.org>]

Muneyoshi,

Thank you for the clarifications. They have resolved my
questions.

About the dedicated router approach -- as I understand it,
in it there is a dedicated physical router per customer,
which then interfaces with a provider router (say via BGP).
(The dedicated physical routers per customer, together with
the corresponding provider router to which they connect, are
equivalent to a "PE" router.) 
The provider network is not assumed to be MPLS-enabled,
so all P/PE routers need to be BGP peers, and thus learn
of all customer routes in all VPNs.

I suspect that based on your explanation of why access lists
are out of scope of PPVPN, the above approach may be out-of-scope
as well?

Regards,
-Vishal

> -----Original Message-----
> From: Muneyoshi Suzuki [mailto:suzuki.muneyoshi at lab.ntt.co.jp]
> Sent: Wednesday, June 23, 2004 4:41 PM
> To: v.sharma at ieee.org
> Cc: suzuki.muneyoshi at lab.ntt.co.jp; L3PPVPN; Ross W. Callon
> Subject: Re: Distribution of VPN routing info. to P routers
> 
> 
> 
> Vishal,
> 
> > Sec. 3.2.1. of the L3 PPVPN framework draft states that:
> > 
> > "Note that VPN routing information is never distributed to the P
> >    routers.  VPN routing information is known at the edge of the VPN
> >    backbone, but not in the core."
> > Is there an implicit assumption here that the PE-PE route 
> distribution is
> > always via an i-BGP connection?
> 
> No. The framework document covers L3 PE- and CE-based VPNs, and the 
> former include "2547bis" and "VR" approaches. In CE-based and VR cases,
> customer routing information is transferred by tunnels among PEs. In the
> 2547bis case, it is distributed via BGP protocol in provider network.
> 
> > Since the framework covers L3 PPVPNs in general, does it not inclue 
> > the "older" or more naive ways of building PPVPNs, such as the shared
> > router (access lists) and dedicated router (split routing) approaches,
> > which would have to allow the core (P) routers to know of customer
> > routes?
> 
> Access lists approach is out of scope of PPVPN, because it is not 
> practical for public service. Customers may assign private IP address
> spaces inside customer network, but this approach can not
> identify duplicated private address spaces among customers.
> 
> I'm not sure dedicated router approach, but if it means VR approach,
> it is clarly addressed in the framework document. 
> 
> Thanks,
> 
> 
> Muneyoshi Suzuki
> Nippon Telegraph and Telephone Corp.
>