I have two sites A and B as the following:
MPLS WAN MPLS WAN
Site A ------------ Site B
Site A routing: OSPF area 1 internally, OSPF area 0 with Site B. EIGRP into WAN.
Site B routing: OSPF area 2 internally, OSPF area 0 with Site A. EIGRP into WAN.
Routing requirement is WAN as the primary route for A to reach B and vice versa, and the backdoor link as backup.
Both sites have OSPF intra-area and external routes. When those routes are redistributed into EIGRP, they become EIGPR external routes when received by the other site. EIGRP external has higher administrative distance than OSPF routes via the backdoor link.
I have tried EIGRP summary routes and OSPF inter-area summarization. But the problem is OSPF "area range" command don't handle A or B's OSPF external routes. I'm thinking about the following two tricks. Can someone tell me if it works?
Option 1: if site A has an OSPF External route as 10.20.1.0/24, the route will be redistributed into EIGRP to be sent into WAN. I can add a EIGRP summary route as itself. Because EIGRP summary route is carried as administrative distance 90, this make site B prefers the route coming from WAN over the OSPF from backdoor link.
ip summary-address eigrp 1 10.20.1.0 255.255.255.0
Can a route be summarized to itself?
Option 2: use Leak-map in EIGRP summary route configuration to let 10.20.1.0/24 leak into the WAN cloud:
ip summary-address eigrp 1 10.20.0.0 255.255.254.0 leak-map OSPF-External
route-map OSPF-External permit 10
match ip address 10
access-list 10 permit 10.20.1.0 0.0.0.255
Is the leaked router still carried as administrative distance 90?
Thanks a lot for any help