The Basic Connection: Modem to Router to Devices

Your modem receives the internet signal from your internet service provider. Your router takes that signal and broadcasts it wirelessly to your devices. To connect them, you plug an ethernet cable from the modem's ethernet port into the router's WAN port (sometimes labeled "Internet" or "Uplink"). That single cable is the entire physical connection — everything else happens through settings on the router itself.

The WAN port is different from the regular ethernet ports on the back of your router. On most routers, the WAN port is a different color (usually blue or yellow) and sits apart from the other four ports. If you plug the modem cable into one of the regular ports by mistake, the router will not receive internet, even though the cable is connected.

Key Takeaways

  • The modem connects to the router using a single ethernet cable plugged into the router's WAN port, which is usually a different color from the other ports.
  • Power on the modem first, wait for its lights to stabilize, then power on the router — this order prevents connection errors.
  • After the router boots up, you log into its settings using the default username and password printed on the router's label or in its manual.
  • Changing the router's default password and network name (SSID) from the settings page is the first security step after connection.
  • If the router does not detect internet after 5 minutes, restart the modem by unplugging it for 30 seconds, then restart the router.

What You Need Before You Start

Gather an ethernet cable (usually included with your router), your modem, your router, and a power outlet for each device. Check the back of your router for the WAN port label — if you cannot find it, look at the manual or the manufacturer's website. Most routers have the manual available as a PDF read if you search the model number.

You do not need a computer to make the physical connection, but you will need one (or a phone or tablet) to log into the router's settings afterward. Write down the router's model number and the default login credentials from the label on the back — you will need these in a few minutes.

Step 1: Power Down Everything and Gather Your Cables

Unplug your modem and router from power. This prevents electrical issues when you are plugging cables in. Lay out both devices where they will sit permanently — do not move them around once they are powered on, as this can interrupt the connection while the modem is syncing with your ISP's network.

Have the ethernet cable ready. If you do not have one, any standard ethernet cable works — length does not matter for performance, so a 25-foot cable works the same as a 3-foot cable.

Step 2: Connect the Modem to the Router With One Ethernet Cable

Plug one end of the ethernet cable into the modem's ethernet port. Most modems have only one ethernet port, so there is no choice about which one. Plug the other end into the router's WAN port — the one that is usually a different color or labeled "Internet" or "Uplink." Push the cable in until you hear a click; the connector should sit flush against the port.

Do not plug the cable into one of the router's regular ethernet ports. Those ports are for connecting devices like computers or printers to the router — they do not receive internet from the modem.

Step 3: Power On the Modem and Wait for Lights to Stabilize

Plug the modem into power. You will see lights turn on when ready. Wait 2 to 3 minutes for the lights to stop blinking and settle into a steady pattern. The modem is syncing with your ISP's network during this time. Do not plug in the router yet — this order matters because it prevents the router from trying to connect before the modem is ready.

Look for a light labeled "Online," "Internet," or "Ready." When that light is solid (not blinking), the modem has a working connection. If that light never comes on after 5 minutes, your modem may not be receiving a signal from your ISP. Check that the coaxial cable (the thick cable from the wall) is plugged firmly into the modem's coax port.

Step 4: Power On the Router and Wait for Boot-Up

Once the modem's lights are stable, plug the router into power. The router's lights will flash as it boots up. Wait 2 to 3 minutes for the lights to settle. You should see a light for the WAN connection turn on — this means the router has detected internet from the modem. If the WAN light does not come on after 5 minutes, unplug the router, wait 30 seconds, and plug it back in.

While the router is booting, you can open a web browser on a phone, tablet, or computer that is near the router. You do not need to connect to the network yet — just have the browser ready.

Step 5: Log In and Change the Default Settings

Once the router has finished booting, look at the label on the back of the router. It will show a default network name (SSID) and a default password. Open a web browser and type the router's IP address (usually 192.168.1.1 or 192.168.0.1 — check the label) into the address bar. A login page will appear.

Enter the default username and password from the label. Once you are logged in, find the section for "Wireless Settings" or "Network Name" and change the default network name to something you will recognize. Then find "Security" or "Password" and change the default password to something only you know. Save the changes. The router will restart, and you are done with the connection.

What to Do If the Connection Does Not Work

If the router does not show an internet connection after 5 minutes, restart both devices in order: unplug the modem, wait 30 seconds, plug it back in, wait for its lights to stabilize, then unplug the router, wait 30 seconds, and plug it back in. This fixes most connection problems.

If the lights still do not show a connection, check that the ethernet cable is plugged into the modem's ethernet port and the router's WAN port — not a regular port. If the cable is in the right place, try a different ethernet cable. If a different cable works, the original cable is damaged. If the problem continues, contact your internet service provider to confirm the modem is receiving a signal from their network.

Frequently Asked Questions

Do I need to use an ethernet cable, or can I connect wirelessly?

The modem and router must be connected with an ethernet cable. Wireless connection between them is not an option. However, once the router is set up, your devices (phones, laptops, tablets) connect to the router wirelessly.

What if my router does not have a WAN port?

All routers have a WAN port, but on some models it may be labeled differently or combined with the regular ports. Check the manual for your specific model. If you cannot find the label, search the model number online — the manufacturer's website will show a diagram of the ports.

Can I use a longer ethernet cable between the modem and router?

Yes. Ethernet cable length does not affect internet speed or reliability for distances under 100 feet. Use whatever length you need to reach from the modem to the router.

Why do I need to change the default password?

The default password is printed on thousands of routers of the same model. Anyone with that model number can log into your router's settings and change your network, see connected devices, or block your internet. Changing it to a unique password prevents this.

What if I do not know my router's default password?

The default password is on the label on the back of the router. If the label is worn or missing, look up the model number on the manufacturer's website — they publish default credentials for every model. If you have already changed the password and forgotten it, you can reset the router to factory defaults by holding the reset button (usually a small hole on the back) for 10 seconds while the router is powered on.