First, check the basics—look for power issues on your optical network terminal and inspect all cables for visible damage. Many fiber internet problems come from dirty connectors or loose plugs, not major faults. To connect your fiber optic cable to a router, ensure you have the following: Fiber optic modem (ONT): Most fiber connections require an Optical Network Terminal (ONT), provided by your ISP. This guide details the necessary physical and digital steps to connect your fiber line and activate your internet service. Despite multiple attempts, the Archer AX6000 v1.