Question 470
Switches on one Rapid PVST+ VLAN instance advertise these bridge IDs: SW-1 (priority 32768, MAC 2c1a55ffffed); SW-2 (priority 8192, MAC 8899498771f3); SW-3 (priority 4096, MAC 3460772e5a65); SW-4 (priority 24576, MAC 344da88b8ce2). They are powered on with no previous root. Which switch is the elected root?
Explanation
Correct Answer
The STP root is the switch with the numerically lowest bridge ID: priority is compared first, followed by MAC on ties. SW-3 has the lowest priority 4096.
Incorrect Answers
Its advertised priority is greater than the winner 4096, and no tie breaker changes the result.
That explanation does not distinguish this option. “SW-1 (priority 32768, MAC 2c1a55ffffed)” is an alternative action, but it does not by itself establish the outcome required in this case.
That explanation does not distinguish this option. “SW-4 (priority 24576, MAC 344da88b8ce2)” is an alternative action, but it does not by itself establish the outcome required in this case.