If the Ethernet LED of your router is off, it indicates that no device is connected to the Ethernet port of the router. On the other hand, if there is a solid color light, it indicates that the device is powered on and is connected to the Ethernet port of the router. In case there is a blinking Ethernet LED, it indicates that the port is sending and receiving the traffic. As already mentioned a red light on the Ethernet port will indicate issues with the router. If you are seeing the red light on the Ethernet port, here are a few things that you can try to resolve the issue.