Re: Distribution of VPN routing info. to P routers

[Muneyoshi Suzuki <suzuki.muneyoshi at lab.ntt.co.jp>]

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.