When does the Link LED light up?

The Link LED lights up when a cable is properly connected and powered on, indicating that there is a physical connection between devices, such as a computer and a switch or router. This status light provides a visual confirmation that the network interface is active and ready for communication.

When the Link LED is illuminated, it shows that the networking hardware has successfully established a connection, which is crucial for establishing any data transmission. The illumination of this LED typically does not indicate whether data is being transmitted or received; rather, it serves as an indication that the connection is intact and functioning correctly.