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. Fiber optic internet delivers blazing-fast speeds and reliable connectivity, making it a top choice for modern homes and businesses. However, setting up a fiber optic connection to your router can seem daunting if you're unfamiliar with the process. Think you know your routers from your. I have a modem, conected to a switch and one of those switch cables conected into my D-LINK DIR-825 router (Firmware 7. I tested this cable without router and get 300mbps in my desktop, but when I connect the cable in my router, the lan and wifi connections are limiteds to 100mbps.