The OSPFv3 neighbor adjacency is formed by sending and receiving the hello packet to the neighbor router. To identify the neighbors, OSPFv3 uses router-id. The protocol has to be enabled on per-link basis. This document discuss about the common issues that occurs when forming neighbor adjacency and how to troubleshoot them.
It is assumed that the reader has an understanding of IPv6 and OSPF routing protocol.
The three routers (R1and R2 ) in the network diagram are connected via serial interfaces communicate with each other using OSPFv3.The routers are configured with loopbacks and OSPFv3 is advertised on each interface using the command ipv6 ospf <process id> area <area id>.
Please see attached files Router R1and Router R2
Note: All configurations are tested on Cisco 7200 Router running IOS 15.0(1)M5 software.
Step1. Area ID
Symptom Error Message:%OSPFv3-4-AREA_MISMATCH: Received packet with incorrect area from FE80::C801:5FF:FEF8:0, Serial1/0, area 0.0.0.0, packet area 0.0.0.1
Note: As seen from the output, the interface serial1/0 which is connecting to the router R2 is configured in area 0, however Router R2 (packet area 0.0.0.1) as indicated by the error message is configured to be in area 1.
Check for authentication being used on the OSPFv3 process.The authentication type has to be the same between neighbors. For example, in the case of MD5, the passwords and key should be the same.Also check whether the authentication is enabled on all routers within the area.You can use the command show ipv6 ospf <process id> to check whether authentication is enabled in OSPFv3.
Note: In the above output, the OSPFv3 uses MD5 authentication.
Step5. Network Type
Check the OSPFv3 network type by using the command show ipv6 ospf. The interfaces should be configured of the same network type.