A branch prefix is unreachable, and the engineer needs to see whether that prefix is installed in the edge router. Which display answers the question?
Select an answer to reveal the explanation.
Short Explanation
You want the router's list of places it knows how to send traffic, and whether this branch is on that list. That list is the routing table. A VLAN membership screen, a name lookup, and a cable report do not show whether the prefix is installed.
Full Explanation
The routing table lists the prefixes the router will forward and the next hop for each. The engineer needs to know whether the branch prefix is installed, so the routing table display is the one that answers. The VLAN display lists Layer 2 VLAN membership. It does not list Layer 3 prefixes. A DNS lookup resolves names. It does not show the routes installed on a router. A cable certifier measures a physical run. It does not report a routing table. Exam caveat: a prefix can be in the table and still be unreachable if the next hop is down. Seeing the prefix is the first question, not the last. Operational check: find the prefix in the routing table, note the next hop and the source of the route, and then test that next hop. Note the next hop for the prefix and test that hop before you call the branch fixed. A prefix that is present with a dead next hop is a different fault from a prefix that is missing entirely.