Refer to the exhibit. All the displayed switches are Cisco 2960 switches with the same default priority and operating at the same bandwidth. Which three ports will be STP designated ports? (Choose three.)

• fa0/21 (SW3): This is a designated port, which implies that SW3 has a lower path cost to the root bridge for that segment, or it could be that SW3 has a lower bridge ID than SW2 for that particular network segment.
• fa0/10 (SW1): This port being designated suggests that SW1 is the root bridge for the segment it shares with SW2 since it has a lower bridge ID, which in this case is determined by the MAC address.
• fa0/13 (SW3): For this port to be designated, it would mean that for the segment between SW1 and SW3, SW3 has the superior bridge ID (lower MAC address in this context) or a lower path cost to the root bridge, assuming all else is equal.

Given that all switches are said to have the same priority and bandwidth, the bridge ID (which consists of the priority and MAC address) would be the deciding factor here, assuming there are no other path cost differences.

It’s important to note that the actual selection of designated ports in an STP environment can be influenced by various factors beyond priority and MAC addresses, including port costs and port priorities, which are not visible in the information provided.