LAN Cable to WiFi Router: WAN, LAN and Cable Choice
A router has two kinds of socket and they are not interchangeable. Plugging a device into the wrong one produces no connection and a lot of confusion.
Quick Answer
| Port | Connects to | Use |
|---|---|---|
| WAN, often blue or labelled internet | Modem or the incoming line | Brings the internet into the router |
| LAN, usually numbered | Your devices | Wired connections to computers, consoles, TVs |
| Uplink or WAN LAN combo | Either, auto sensing | Check the label |
| USB port | Storage or a printer | Shared storage, not networking |
A device cable goes into a numbered LAN port. The WAN port is for the incoming connection only.
Cable Choice
Cat5e
Fine for gigabit at domestic lengths and the cheapest option.
Cat6
Better headroom and shielding, suitable for most modern installs.
Cat6a
For 10 GbE over longer distances. Thicker and stiffer.
Length
Up to 100 metres total channel. In a home, any practical length works.
Setup and Checks
- Connect the device to a numbered LAN port.
- Confirm the link lights on both ends.
- Check the device reports a wired connection.
- Confirm the negotiated speed in the router interface.
- Only then connect the WAN port to the modem, if setting up from scratch.
Real-World Applications
- Consoles and smart televisions where wireless is congested.
- Desktop computers in a home office.
- Printers that need a stable address.
- Mesh nodes wired back to the router.
Related Guides
For cable types, read RJ45 or RJ11. For fibre runs, see fiber optic to Ethernet. For adapters, start with Ethernet cable for MacBook.
FAQ
Can I plug a computer into the WAN port?
No. The WAN port expects the incoming internet connection.
Which cable should I buy?
Cat6 for most home use. Cat5e is adequate for gigabit at short lengths.
Why is there no link light?
Wrong port, dead port, or a damaged cable. Swap ports before replacing the cable.
Does the cable affect WiFi speed?
No. It provides a separate wired path.