We have a carrier supplied MPLS WAN running BGP on the PE routers redistributed to our LAN EIGRP on layer 3 switches at all locations for advertising routes everywhere on the WAN. Recently we added a couple wireless connections between sites to provide higher speed connections between them and backup WAN links in the event of the MPLS connections going down on one end or the other of these sites. The problem we have now is that when a site with no wireless, just the MPLS connection goes down, the route to the site that is down gets advertised over the wireless connections and creates a routing loop. This became appearent when I attempted to setup a backup VPN connection to one of these sites without wireless. Once the site that lost connectivity comes back up, routing still attempts to go through the wireless connections until I clear eigrp neighbors at those wireless site l3 switches.
I've been searching for the answer to my problem and believe that I may need some access lists for the wireless routes so that the MPLS doesn't distribute them, but I'm not sure if this is the solution or not. I need the wireless connections to be available as what someone else referred to as "backdoor routes" as well as the preferred routes between the P2P wireless sites.
