OSPFv3 vs OSPFv2

link based not network based

router and link IDs are address family independent
multi-protocol possible
Packet authentication gone
needs to be ensured by L3 (IPSec)
multicast IPSec = fun fun fun
additional link types
Link LSA
Intra Area Prefix
more complex flooding options
link local, area wide, AS wide
works even for unknown LSA (yikes!)