Observe the exhibit. If the command variance 3 were added to RTE, which path or paths would be chosen to route traffic to network X?
正解:B
Explanation/Reference: Explanation: Advertised distance of RTD is greater than FD of RTE-RTC-RTA, so the route through D will not be used. Please notice that routes must first satisfy the feasible condition to be considered for "variance" command: The feasible condition states: "To qualify as a feasible successor, a router must have an AD less than the FD of the current successor route". In this case, the current successor route is E -> C -> A and the FD of this successor route is 20. But the AD of route E-D-A is 25 which is bigger than the FD of the successor route -> It will not be put into the routing table even if the "variance 3" command is used.