If PC-A is unable to communicate with PC-B, and they are both in VLAN 60, what might be the issue?

If PC-A is unable to communicate with PC-B, and they are both in VLAN 60, what might be the issue?

• A. The devices are on different subnets
• B. The VLAN used by PC-A is not in the list of allowed VLANs on the trunk
• C. There is a physical connectivity issue
• D. Both devices are configured with identical IP addresses

Answer: (B)

When PC-A and PC-B are supposed to communicate within the same VLAN, specifically VLAN 60 in this case, but are unable to do so, one common reason could be that the VLAN used by PC-A is not in the list of allowed VLANs on the trunk link between switches. In VLAN configurations, trunk ports are used to allow multiple VLANs to pass through a single link between switches. If VLAN 60 is not allowed on the trunk link, devices in that VLAN will not be able to communicate with each other even if they are configured correctly on their respective switches. The presence of the correct VLAN on the trunk is crucial for VLAN-tagged traffic to traverse the network. Therefore, even if both devices are connected properly and configured for the same VLAN, if VLAN 60 is not permitted on the trunk link, their communication will effectively be blocked, resulting in a failure to send or receive data. This understanding helps to diagnose VLAN issues effectively and emphasizes the importance of proper trunk configurations in VLAN environments.

When PC-A and PC-B are supposed to communicate within the same VLAN, specifically VLAN 60 in this case, but are unable to do so, one common reason could be that the VLAN used by PC-A is not in the list of allowed VLANs on the trunk link between switches. In VLAN configurations, trunk ports are used to allow multiple VLANs to pass through a single link between switches. If VLAN 60 is not allowed on the trunk link, devices in that VLAN will not be able to communicate with each other even if they are configured correctly on their respective switches.

The presence of the correct VLAN on the trunk is crucial for VLAN-tagged traffic to traverse the network. Therefore, even if both devices are connected properly and configured for the same VLAN, if VLAN 60 is not permitted on the trunk link, their communication will effectively be blocked, resulting in a failure to send or receive data.

This understanding helps to diagnose VLAN issues effectively and emphasizes the importance of proper trunk configurations in VLAN environments.