If you encounter issues, reset your router and verify all cables and settings. Consult your ISP's customer support if problems persist, as they can guide you through specific configurations or troubleshooting steps. 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. Despite multiple attempts, the Archer AX6000 v1. The blue light on top of the router spins around for a. To set up your router for fiber internet quickly, connect the router to your fiber modem, access the router's settings via a web browser, and input the provided ISP credentials.