Using new backup router in spite of faulty one in ospf domain but relationship with neighbor in one interface only not working , what is the reason of this problem? (Choose 2)
A. area Id mismatch
B. authentication mismatch
C. process id of ospf not match
D. OSPF timers not match
Answer is A and D .
The question doesn’t mention AUTHENTICATION
so the next best logic is to pick what is most likely to be misconfigured.
Both area and timers can be configured at interfaces level.
B can be configured under router ospf or under the interface
D is configured under the interface.
A can be configured under the router ospf or under the interface.
Hence, question is not clear.
B and D, any area can mismatch with area 0 and still form neighbor.
A,B – interfaces command.
Answer A-B-D
https://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/7039-1.html#t18
In this question we have 3 correct choices.
A
B
D
https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_ospf/configuration/xe-16/iro-xe-16-book/iro-cfg.html