Subject: Re: Question

From: Moiz Moizuddin <[email-masked]>
Date: Thu, 23 Aug 2001 20:19:43 -0700

Loureiro
According to RFC 2547 Sec 4.1

"A given per-site forwarding table will only have one VPN-IPv4 route for 
any given IPv4 address prefix. When a packet's destination address is 
matched against a VPN-IPv4 route, only the IPv4 part is actually matched. "

So if we were to install two prefixes in a particular vrf  we will do the 
normal ipv4 bgp selection process

Thx
Moiz

At 06:13 PM 8/23/2001 -0300, Loureiro, Rodrigo - (Bra) wrote:

>Hi all,
>
>A have a question regarding the VPNv4 address space and the BGP decision 
>algorithm.
>
>Suppose that i have two VPNv4 prefixes in a VRF, with the same ipv4 prefix 
>but different RDs. How does BGP decision algorithm face it ?
>
>I think that one and just one ipv4 prefix should be chosen in order to 
>populate the forwarding component, but how can BGP decide it if the 
>prefixes are different in the VPNv4 point of view ?
>
>Also, imagine that i have an inter-as VPN/MPLS interconnection. Suppose 
>that i have an extranet transversing the two providers and that all VPN 
>sites are connected to both providers for redundancy. Each site advertises 
>the same prefix to both providers and the prefixes are imported in the 
>inter-as connection. How will BGP decide between the two prefixes inside 
>one of the providers ?
>
>
>Thanks,
>--
>
>Rodrigo Loureiro