To connect a fiber optic cable to a Xiaomi router, you first link the fiber to an ONT, then use an Ethernet cable to connect the ONT to the router's WAN port.

Step 1: Prepare Your Equipment

• Optical Network Terminal (ONT): Most fiber connections require an ONT provided by your ISP, which converts the optical signal into an electrical signal your router can use .
• Xiaomi Router: Ensure your router has a WAN port or supports fiber input via an SFP/PON module if it's fiber-ready .
• Cables: You will need the fiber optic cable (SC/APC or SC/UPC connectors) and a high-quality Ethernet cable (Cat6a or higher recommended) to connect the ONT to the router .

Step 2: Connect the Fiber Optic Cable

1. Locate the fiber wall outlet where your ISP's fiber line enters your home.
2. Remove protective caps from both the fiber cable and the ONT's optical port.
3. Carefully insert the fiber cable into the ONT's optical input port, aligning the connector key and pushing until it clicks securely .

Step 3: Link the ONT to the Xiaomi Router

1. Use an Ethernet cable to connect the ONT's LAN or Ethernet output port to the WAN port on your Xiaomi router .
2. Ensure both devices are near a power source and in a dry, ventilated area.

Step 4: Power On and Configure

1. Power on the ONT first and wait for the status lights to stabilize, indicating a successful connection to your ISP .
2. Power on the Xiaomi router and wait for its indicator lights to confirm connectivity.
3. Access the router's admin panel via a web browser (usually at 192.168.31.1 for Xiaomi routers) and enter your ISP credentials if required .
4. Update the router firmware to ensure optimal performance and security.

Step 5: Test the Connection

• Verify that your devices can access the internet.
• If the connection fails, check the fiber and Ethernet connections, ensure the ONT is powered, and confirm the router settings match your ISP's requirements . By following these steps, your Xiaomi router will be properly connected to a fiber optic internet line, providing high-speed, low-latency connectivity for your home network.