On the switched network shown in the figure, STP is enabled on all devices. SW1 is the root bridge. The port costs are shown in the figure. Other parameters retain the default values. After the network is stable, which of the following RPC values is calculated by SW4 for the path to SW1?

Select an option, then click Submit answer.
Reference / correct answer:
Most accepted answer: C. 40
Community votes: C=1
Selected Answer: C The marked answer (A, 50) is incorrect. STP selects the path with the lowest cumulative Root Path Cost, not the one with the fewest hops. The direct SW4→SW1 link costs 50, but the path SW4→SW3→SW1 sums to 30 + 10 = 40, which is lower. SW3 has a very cheap uplink to the root (cost 10), so routing through it beats the direct link. SW4's RPC is therefore 40 → answer C. upvoted 1 times