Which command do you enter to enable authentication for OSPF on an interface?
A. router(config-if)#ip ospf message-digest-key 1 md5 CISCOPASS
B. router(config-router)#area 0 authentication message-digest
C. router(config-router)#ip ospf authentication-key CISCOPASS
D. router(config-if)#ip ospf authentication message-digest
https://networklessons.com/ospf/how-to-configure-ospf-md5-authentication
Correct answer is D.
The correct answer is D
https://community.cisco.com/t5/networking-documents/ospf-authentication/ta-p/3131640
To enable OSPF MD5 authentication:
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#interface fa0/0
Router(config-if)#ip ospf message-digest-key 1 md5 cisco@123
Router(config-if)#exit
Router(config)#router ospf 100
Router(config-router)#area 2 authentication message-digest
Router(config-router)#exit
To enable clear text authentication
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#interface f0/0
Router(config-if)#ip ospf authentication-key cisco@123
Router(config-if)#exit
Router(config)#router ospf 100
Router(config-router)#area 2 authentication
Router(config-router)#exit
Interface based authentication Example:
To enable OSPF MD5 authentication:
Router(config)#int fa0/0
Router(config-if)#ip ospf authentication message-digest
Router(config-if)#ip ospf message-digest-key 1 md5 cisco
Router(config-if)#exit
Router(config)#
To enable clear text authentication
Router(config)#int fa0/0
Router(config-if)#ip ospf authentication
Router(config-if)#ip ospf authentication-key cisco
Router(config-if)#exit
Router(config)#
Correct is “B”
Michal the question “on an interface?”