I have a design issue for which I really like your help.
In a MPLS network there are twoPOP gateway routers (G1,G2) peering with various MPLS VPN Service providers via B2B vrf eBGP peering are in 4 different ASN's. They inturn all peer via VPNv4 eBGP with the Core ASN which comprises of 2 Nos VPNv4 RR's and every site in the ASN haveing 2 P/PE per site. Every P/PE is peering via VPNv4- iBGP with the VPNv4 RR's. The RR's are not in the forwarding path of the traffic.
Every site has 2 Nos CE routers and each CE router does a vrf based ebgp peering with the P/PE's.
The P/PE routers import 2Nos RT exported by the 2 Nos POP G/w routers and inturn selects the best path and pass it to the CE routers.
Now it is seen that the P/PE of all sites is selecting the best path adverstised by G1 instead of G2 based on the AS PATH length and the shortest path is being adverstised by G1. So till a situation arises that the G1 is down till that time the P/PE's are forwarding the outbound traffic from the CE to G1 even also when the IGP cost is adding up high and when there is a direct link failure from the P/PE site to G1 site.
It therefore makes sense that if the direct physical link form a P/PE site to the site G1 is located goes down ,the P/PE's then should choose G2 via another path even when G1 is available.
Does these sort of requirements ever come in SP environments from customers ? if so what are the solutions ..
Thanks in advance