What is the result of port isolation on a switch?

Port isolation on a switch is a feature designed to limit the communication between devices connected to the switch. When port isolation is enabled, it restricts ports within the same VLAN from communicating with one another, effectively isolating them. This means that devices on isolated ports cannot send or receive traffic from each other while still being able to communicate with devices outside the isolated ports through a shared gateway.

The correct choice reflects this functionality by stating that it isolates communication within the same VLAN. In practical terms, this is useful in scenarios where security is a concern or when it's necessary to limit broadcast traffic between devices that generally might not need to communicate directly with one another.

The other options do not accurately describe the nature of port isolation. For example, enabling unrestricted communication in the same VLAN contradicts the very purpose of port isolation, which is to limit communication. Similarly, assertations regarding its application only to different VLANs or that it doesn’t affect VLAN communication entirely fail to capture the essence of how port isolation operates within a switch. Therefore, understanding port isolation's function clarifies why isolating communication within the same VLAN is the appropriate result.