If your router's red light is blinking, start by power cycling it—turn it off, wait a few seconds, then turn it back on. Check your cables and connections to make sure everything's secure, and if needed, reset your router to factory settings. The LOS light on your router indicates the status of your internet connection to the Internet Service Provider (ISP). However, when it blinks red or stays solid red, it signifies a Loss of Signal, a problem preventing your router from communicating. However, a common concern among users is a router flashing red.