Displaying OSPF Link States

B

The correct answer to the question is B. show ip ospf database.

The OSPF (Open Shortest Path First) protocol is a popular routing protocol used in many networks. One of the key features of OSPF is its ability to build a topology map of the network by exchanging link-state advertisements (LSAs) with other routers in the same OSPF area. Each router maintains a copy of the LSAs it receives and uses them to build a complete picture of the network topology.

The show ip ospf database command displays the contents of a router's OSPF database, which includes all the LSAs received by the router. This command can be used to examine the topology map and troubleshoot OSPF-related issues.

Option A, show ip ospf neighbors, displays a list of the OSPF neighbors that a router is currently connected to. This command is useful for verifying that OSPF neighbor relationships are established and active.

Option C, show ip ospf link-state, is not a valid command. The correct syntax is show ip ospf database.

Option D, show ip ospf Isa database, is also not a valid command. There is no such thing as an "Isa database" in OSPF.

In summary, the correct command to display the collection of OSPF link states is B. show ip ospf database.