Interface level command ip ospf authentication message-digest (Enable MD5 authentication) ip ospf message-digest-key 1 md5 cisco ip ospf authentication (Enable clear text authentication) ip ospf authentication-key cisco OSPF authentication type Type 0: Null, no authentication Command: ip ospf authentication null Type 1: Clear text Command: ip ospf authentication Type 2: MD5 hash authentication Command: ip … Continue reading OSPF: A note about OSPF authentication →