Xiaomi routers do not have a direct fiber optic port; the fiber line connects to an ONT, and the router's WAN port is used to link to the ONT.

How to Connect Fiber to a Xiaomi Router

1. Use an Optical Network Terminal (ONT): Most fiber internet setups require an ONT provided by your ISP. The fiber optic cable from the wall outlet plugs into the ONT's fiber port .
2. Connect the Router via WAN Port: Once the ONT is powered on and active, use an Ethernet cable to connect the ONT's LAN port to the WAN port on your Xiaomi router. The WAN port is usually labeled “Internet” or “WAN” on the back of the router .
3. Power On and Configure: Turn on the Xiaomi router. Access the router's admin panel (e.g., router.miwifi.com) to configure your network settings and enter any ISP credentials if required .

Notes

• Direct Fiber Ports: Only certain high-end routers with SFP modules support direct fiber connections. Standard Xiaomi consumer routers like the Mi Router 4C or AX3000T rely on the WAN port connected to an ONT .
• Cable Type: The fiber cable is typically thin and yellow with SC/APC or SC/UPC connectors. It should never be plugged directly into the router unless the router explicitly supports SFP/fiber input .
• Troubleshooting: If the internet does not work after connecting, ensure the ONT is active, the Ethernet cable is properly seated, and the router's WAN settings match your ISP requirements . In summary, for Xiaomi routers, the fiber optic line goes into the ONT, and the router's WAN port is used to connect to the ONT to provide internet access to your devices.