A. 10 seconds
B. 30 seconds
C. 30 minutes
D. 1 hour
Explanation: Each LSA has its own age timer. By default, an LSA waits for 30 minutes before requiring an update. So to make sure that each router first has an up-to-date LSA, OSPF refreshes LSAs after every 1 hour.
A. Packet length
B. Router id
C. Authentication type
D. Maxage time
Explanation: The packet length field gives the length of the packet in bits. The Authentication type field gives the type of authentication used. The router ID field gives the ID of the source router of the packet. In an OSPF packet header, there is no field called Maxage time.
A. ?[network mask] area [area-id]? and ?router ospf [process-id]?
B. ?[wildcard-mask] area [area-id]? and ?[network mask] area [area-id]?
C. Only ?router ospf [process-id]?
D. ?[wildcard-mask] area [area-id]? and ?router ospf [process-id]?
Explanation: The “Router ospf [process-id]” command enables OSPF routing protocol in the router and the “[Wildcard-mask] area [area-id]” command is used to select the interfaces that we want to include in the OSPF process. That is enough for the basic configuration of OSPF in a router.
A. Show ip ospf interface
B. Show ip ospf
C. Show ip route
D. Show ip ospf neighbor
Explanation: The “Show ip ospf neighbor” command is the OSPF show command that can describe a list of OSPF adjacencies i.e. the list of adjacent nodes or neighbors. The router will only communicate with its neighbors directly.