Where to plug the fiber optic port into the router

The router should be plugged into the WAN port using an Ethernet cable from the Optical Network Terminal (ONT), or directly into an SFP/SFP+ port if the router supports fiber modules.Standard Fiber Setup with ONTMost residential fiber connections require an Optical Network Terminal (ONT) provided by your ISP, which converts the optical signal from the fiber into an electrical signal that your router can use . The correct connection sequence is:Fiber Cable to ONT: Plug the fiber optic cable from the wall outlet into the ONT's optical port, usually labeled “Fiber” or “GPON” .ONT to Router: Use a standard Ethernet cable (Cat5e or Cat6) to connect the ONT's Ethernet/LAN port to the WAN or Internet port on your router. This port is often colored differently (blue or yellow) and labeled “WAN” .Power Up: Turn on the ONT first, wait for the status lights to stabilize, then power on the router .Direct Fiber Connection via SFP/SFP+ PortSome advanced routers support fiber modules (SFP or SFP+) that allow the router to connect directly to the fiber network without a separate ONT . In this case:Insert the SFP/SFP+ module into the router's SFP/SFP+ port.Configure the SFP interface as the WAN port in the router's settings.Ensure the module is compatible with your ISP's fiber type (GPON, PON, or Ethernet over fiber), .Key ConsiderationsDo not plug the fiber cable directly into a standard router's Ethernet port unless it has a compatible SFP/SFP+ module .Handle fiber connectors carefully to avoid dirt or damage, as this can degrade signal quality .Place the ONT and router near power outlets and in a dry, ventilated area .After connecting, log into the router's admin panel to configure ISP credentials or VLAN settings if required . By following this setup, your router will correctly receive the internet signal from the fiber network, either through the ONT via the WAN port or directly via an SFP/SFP+ module.