I work in a large enterprise. We run our own MPLS environment for macrosegmentation. See attached diagram.
We are converting from EIGRP to OSPFv2 at our remote sites. Remote sites are running their own single-area OSPF instances (no area 0). We have one site that is having problems with its metro-E connectivity on PE2. So its iBGP session to the RR is down. PE1 is advertising a redistributed static summary route, 10.72.168.0/22, into VPNv4.
We have our general production VRF (called VRF PROD in the diagram). When PE1/PE2/CE1 were running EIGRP and OSPF in parallel, I was able to contact PE2's VRF PROD loopback from RS CE. When I turned off EIGRP for PE1/PE2/CE1, I was no longer able to reach PE2's VRF PROD loopback. PE2 no longer had a default route.
We are not redistributing BGP into OSPF. We are letting the CEs see site detail, and a default route, and that's it. The result is LSA type 1s and an LSA type 5 for the default route.
OSPF relationships are as implied in the diagram. PE1/PE2/CE1 have VRF PROD relationships in a triangle. They are all point-to-point. PE1 is configured with default-information originate. PE2, because of the BGP session problems, is not. CE1 is configured with capability vrf-lite. PE1 and PE2 are NOT configured with capability vrf-lite since they are the PEs. I would expect PE2 would not install PE1's default route if the down bit were set, but the down bit is not set. The routing bit is not set. Here is the output from the database for 0.0.0.0/0
PE2#show ip ospf 12 database external 0.0.0.0
OSPF Router with ID (10.72.171.242) (Process ID 12)
Type-5 AS External Link States
LS age: 1614
Options: (No TOS-capability, DC, Upward)
LS Type: AS External Link
Link State ID: 0.0.0.0 (External Network Number )
Advertising Router: 10.72.171.241
LS Seq Number: 8000015D
Checksum: 0xFFAD
Length: 36
Network Mask: /0
Metric Type: 2 (Larger than any link state path)
MTID: 0
Metric: 1
Forward Address: 0.0.0.0
External Route Tag: 3489725929
I need to understand why PE2 is not installing the default route. Is this expected behavior? If it's not expected behavior, then it points to a software bug. If it IS expected behavior, then I need to understand it so I can assess the impact, and if we need to change our design, at other dual PE sites, for when a PE experiences a BGP session failure.
