We have Sites 1 and 2 connected to our MPLS Provider and also have a Backup link between Site 1 and 2 using a different provider for vendor redundancy. We are running OSPF between all the Sites and the MPLS all in Area 0.
We want all traffic to route through the MPLS and only use the Backup link in the event that the MPLS is down. I know that this is a common problem when using OSPF with MPLS and Back Door links and the answer has been to use a Sham Link. The issue we are running into is that our MPLS provider does not offer this configuration as they are a rather large provider and keep all services “standard”.
Another solution I found was to use BGP as the CE-PE protocol, but the MPLS is actually used to connect other business units regionally and our Regional team wants to keep the CE-PE protocol standard across all units.
I found a few forums with replies suggesting to use 2 processes and then redistribute or to redistribute everything so that it all comes up as E2 but many times the posters never confirm if this worked for them.
Has anyone gotten this working by not using Sham Links or BGP?
