Yesterday, 11:58 AM
When the DCI (Area-0) link fails, the OSPF backbone becomes partitioned. OSPF requires a contiguous Area-0. An OSPF virtual link through the common non-backbone Area-110 stitches the two Area-0 halves back together without ISP changes
A GRE tunnel between S0/0–S0/0 could also carry Area-0, but it’s a workaround. You must build and maintain a tunnel, handle MTU, overhead, and run OSPF over it. The virtual link needs no new interfaces and uses the existing OSPF adjacency in Area-110.
A GRE tunnel between S0/0–S0/0 could also carry Area-0, but it’s a workaround. You must build and maintain a tunnel, handle MTU, overhead, and run OSPF over it. The virtual link needs no new interfaces and uses the existing OSPF adjacency in Area-110.