OSPF Authentication

IOS
router ospf 1
area 0 authentication
!
interface X
ip ospf authentication
ip ospf authentication-key xxx

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IOS
router ospf 1
area 0 authentication message-digest
!
interface X
ip ospf authentication message-digest
ip ospf message-digest-key 1 md5 xxx

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IOS-XR
router ospf 1
authentication-key xxx
authentication
area 0
authentication-key xxx
authentication
interface X
authentication-key xxx
authentication

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IOS-XR
router ospf 1
authentication message-digest
message-digest-key 1 md5 xxx
area 0
authentication message-digest
message-digest-key 2 md5 xxx
interface X authentication message-digest
message-digest-key 3 md5 xxx