Implementing Cisco Network Security (IINS v3.0) (#29)

Which command enables authentication at the OSPFv2 routing process level?

area 0 authentication message-digest
area 0 authentication ipsec spi 500 md5 1234567890ABCDEF1234567890ABCDEF
ip ospf authentication message-digest
ip ospf message-digest-key 1 md5 C1sc0!