Question

You are deploying OSPFv3 on an IOS XR provider edge router that must carry both IPv4 and IPv6 routes over the same set of core links. The IPv6 adjacencies form correctly, but no IPv4 routes are being learned via OSPFv3 even though the interfaces have IPv4 addresses and are enabled for the process. What is the most likely cause?

Accepted Answer

The IPv4 address-family has not been enabled within the OSPFv3 instance, so IPv4 prefixes are not advertised over the shared adjacency.

Answer

OSPFv3 only transports IPv6; a separate OSPFv2 process must be configured to carry the IPv4 prefixes.

Answer

OSPFv3 requires a globally unique 32-bit router ID configured from an IPv4 address, which is missing on the IPv4 interfaces.

Answer

IPv4 routes require the interfaces to be placed in a different area than the IPv6 routes because OSPFv3 cannot mix families in one area.