Yes, you can often use your existing router with fiber optic internet, but there are crucial considerations. Understanding compatibility, potential limitations, and when an upgrade is necessary will ensure you get the most out of your high-speed connection. This guide will break down everything you. Fiber optic networks are celebrated for their speed and reliability, but even the best systems can encounter problems. When issues like signal loss, slow speeds, or intermittent connectivity arise, systematic troubleshooting is key. Despite multiple attempts, the Archer AX6000 v1. Instead of a modem, fiber connections require an Optical Network Terminal (ONT), a device that converts fiber signals into an Ethernet connection. Plus, get same-day or next-day tech appointments for Fiber. Sometimes, those two are combined in a single hardware box called a residential gateway.