Although I have dozens of routers running over a Sprint MPLS network, I am focused on two of them.
We use OSPF to propagate routes throughout our routers and this is working fine.
We also use Demand Dial routing (BRI lines) with floating static routes to bring a remote site up on backups should their T1 go down. This is also working fine.
My problem is, we have one particular remote location that needs more bandwidth than BRI offers.
We brought an Internet T1 into this remote location and setup a Tunnel to our main router (tunnel runs over IPSec). The Tunnel interface is up and routes traffic just fine.
The idea is MPLS would be the first choice for routing traffic, if that T1 goes down and the routes drop out of the routing table then have the routes using the GRE Tunnel float into the routing table. If that Internet T1 goes down too, then those routes drop out and the static DDR route floats into the routing table and brings up the BRI.
This is where I am stuck. I created a second OSPF process on each router to exchange routing information over the Tunnel, but the routes are not propagating. Debug IP OSPF Events shows OSPF is talking over the Tunnel but I don't see any routes.
As a test, I removed the LAN subnets from the first OSPF process (no network x.x.x.x 0.0.0.255 area 0) and then they started working through the second OSPF process.
So it appears I cannot have the same network specified in two OSPF processes.
How can I make this work?
it is true you cannot have the same set of network ... area commands on both OSPF processes.
This because the OSPF v2 hello doesn't contain the process-id so using same network .. area commands make the router unable to understand if a link belongs to OSPF 1 or to OSPF2
you need to configure redistribution between the two processes.
I would suggest to make the second process your edge protocol and to redistribute from OSPF 2 into OSPF1.
Towards the remote you can advertise only a default route using
router ospf 2
default-information originate always
this is to avoid to have mutual redistribution.
consider that O E1 are preferred over O E2 routes and that both are less preferred then O or O IA routes by a single OSPF process.
I wonder if it is possible in your case to deploy a single OSPF process by using artificial high OSPF costs on the GRE tunnel
and even higher costs on the ISDN DDR link.
I may be wrong but this looks like possible.
Hope to help