WAN Routing Question

[Adam Frederick]

Hello,

I am confused on a current scenario and was hoping someone could help me understand why or why not to run an IGP across the WAN in this scenario.

MPLS network will be replacing current point-to-point network which consists of a basic 10 sites.  1 site is hub and 1 site is dr.  Each site has point-to-point to each location and runs EIGRP currently.

In new MPLS setup, each site will peer with AT&T using BGP.

My question is... since we'll be connecting all of the locations with BGP... is there any point in running EIGRP over the WAN?

I will still run it locally on the LAN of course for other peers that are on the LAN, but is there any advantage to running it across the WAN since BGP is running? 

Thanks for any input,

Adam                            

[Giuseppe Larosa · Accepted solution]

Hello Adam,

if the new service is an MPLS L3 VPN service you will likely need to run only eBGP to the PE router in each site.

If it is an MPLS L3 VPN service you will not be able to run EIGRP over the WAN links anymore as you need to peer with the SP PE node at each site.

It is duty of the SP the correct route propagation among your sites.

You will need to redistribute from BGP to EIGRP in each local site.

Redistribution of EIGRP into BGP can be avoided just use the network command under router bgp to advertise local networks

Hope to help

Giuseppe