For LOS (Loss of Signal) red lights on fiber or advanced gateways, it usually means the incoming optical line is not detected or has low signal. Double-check that the fiber line is connected properly and that there's no bend or physical damage. If issues persist, an on-site. Whether your modem is blinking orange, your router has a solid red light, or you are staring at a mysterious "DS" indicator, you will find the answer below. Blinking green typically means data. A blinking red or orange light typically signals an issue with your internet connection or router configuration. When it's green and steady, everything is fine.