R1
int s0/0/0
ip ospf authentication-key cisco
ip ospf authentication
R2
int s0/0/0
ip ospf authentication-key cisco
ip ospf authentication
R1
int s0/0/0
ip ospf message-digest-key 1 md5 cisco
ip ospf authentication message-digest
R2
int s0/0/0
ip ospf authentication message-digest cisco
ip ospf authentication message-digest