in the topology below , SW3 is the Root Bridge.SW4 on the right has 2 interfaces connected to it.
based on what I have read Root Port and blocking port , will be determined based on:
Link Cost = Speed of the interfaces
Bridge ID = in our case SW3 is the Root Bridge
Ports Priority = ??
Port Number= in our case Fa0/21 and Fa0/23
So based on what is the Port Priority is determined ?