5 Requirements for OSPF to form a relationship with a neighbor:
1. Hello and Dead timers must match
2. Network mask must match
3. Area ID must match
4. Authentication password must match (if you are using OSPF authentication)
5. Stub Area Flag must match
Also found a great wiki on OSPF best practices: http://wiki.nil.com/OSPF_area_
The big difference between IPv4 and IPv6 OSPF configuration on a Cisco router is that the initial configuration has moved to the interface level, instead of using the "network" statements to determine which interfaces will be part of the OSPF process. To get IPv6 OSPF up-and-running, here are the 4 basic commands:
Enable ipv6 routing between non-local subnets
router(config)
