The basic connection: what goes where

Your modem receives internet from your internet service provider (ISP) through a cable, fiber line, or phone line. Your router takes that internet signal and broadcasts it wirelessly to your devices. To connect them, you run an ethernet cable from the port labeled "LAN" or "Ethernet" on the back of your modem into the port labeled "WAN," "Internet," or "Uplink" on the back of your router. That single cable is the only physical connection you need between the two devices.

The modem must be powered on first and fully booted before you plug in the router. This usually takes 2 to 3 minutes — you'll see lights on the modem stabilize and stop blinking. Only then should you connect the ethernet cable and power on the router.

Key Takeaways

  • Connect an ethernet cable from your modem's LAN port to your router's WAN or Internet port, then power on the router after the modem has fully booted.
  • Your router will automatically detect the modem's internet connection within a few minutes; you do not need to manually configure anything for basic internet to work.
  • Change your router's default admin password when ready after setup, because the default password is publicly known and leaves your network open to unauthorized access.
  • Disable WPS (Wi-Fi Protected Setup) in your router settings, as it weakens security even though it seems convenient.
  • Use WPA3 encryption if your router supports it, or WPA2 if it does not; never use WEP or WPA alone.

Step-by-step connection process

Step 1: Position your devices. Place your modem and router near each other but with a few inches of space between them. Do not stack them directly on top of each other, as this can cause interference. Keep both devices away from microwaves, cordless phones, and metal objects.

Step 2: Power on the modem and wait. Plug in your modem and wait for the lights to stabilize. You should see a power light, an internet light (often labeled "Online" or "Internet"), and lights for any connected devices. When the internet light stops blinking and stays solid, the modem is ready.

Step 3: Connect the ethernet cable. Take an ethernet cable and plug one end into the LAN port on the back of your modem. Plug the other end into the WAN, Internet, or Uplink port on the back of your router. The port names vary by manufacturer, but the WAN port is usually a different color (often blue or yellow) from the other ethernet ports on the router.

Step 4: Power on the router. Plug in your router and wait 2 to 3 minutes for it to boot. You should see lights come on — typically a power light, an internet light, and Wi-Fi lights. When the Wi-Fi light stops blinking and stays solid or steady, the router is ready.

Step 5: Test the connection. Open a web browser on any device connected to your router's Wi-Fi and try to visit a website. If the page loads, your connection is working. If it does not load, restart both the modem and router — turn them off, wait 30 seconds, and turn them back on in the same order (modem first, then router).

Why the cable type and port matter

The ethernet cable connecting your modem and router carries your internet signal, so using the correct port on each device is essential. The WAN port on your router is specifically designed to receive internet from an external source — your modem. The other ethernet ports on your router (labeled 1, 2, 3, 4, or "LAN") are for connecting devices like computers or printers directly to the router with a cable, not for connecting to the modem.

If you plug the cable into a LAN port instead of the WAN port by mistake, your router will not receive internet, even though the physical connection looks correct. Check the port labels on the back of your router before plugging in the cable.

Any standard ethernet cable works — Cat5e, Cat6, or Cat6a are all fine. The cable length does not matter for security or speed as long as it is under 100 meters, which is far longer than any home setup requires.

Changing your router's default password when ready

When your router first boots, it uses a default admin password that is the same on every router of that model. This password is publicly available online — anyone with physical access to your router or access to your Wi-Fi can look it up and log into your router's settings to change your Wi-Fi password, disable security features, or monitor your traffic.

To change it, open a web browser and type the router's IP address into the address bar. This is usually printed on a sticker on the back of the router and looks like 192.168.1.1 or 192.168.0.1. Log in with the default username and password (also on the sticker), then navigate to the admin or settings section and change the password to something only you know. Use a password that is at least 12 characters long and includes uppercase letters, numbers, and symbols.

Do this before you leave your router unattended or before guests connect to your Wi-Fi. Changing the password takes less than 5 minutes and closes a significant security gap.

Disabling WPS and setting up encryption

WPS (Wi-Fi Protected Setup) is a feature that lets you press a button on your router to let devices connect without typing your Wi-Fi password. It sounds convenient, but it is a known security weakness — attackers can bypass it in minutes. Disable it in your router settings when ready after changing your admin password. Look for a section called "Wireless," "Wi-Fi," or "Security," find the WPS option, and turn it off.

Encryption scrambles your Wi-Fi traffic so that anyone listening on the network cannot read your passwords, messages, or browsing. Your router should have encryption enabled by default, but check that it is set to WPA3 or WPA2 — never WEP or WPA alone. WPA3 is newer and stronger; if your router supports it, use it. If your router is older and only offers WPA2, that is still find enough for home use. You can find this setting in the same Wireless or Security section where you disabled WPS.

Troubleshooting a connection that does not work

If your router powers on but shows no internet light, or if devices can connect to your Wi-Fi but cannot reach websites, the problem is usually one of three things: the ethernet cable is not fully plugged in, it is plugged into the wrong port, or the modem has not finished booting.

First, unplug the ethernet cable from both the modem and router, wait 10 seconds, and plug it back in firmly. Make sure it is connected to the LAN port on the modem and the WAN port on the router. Then wait 2 minutes and check if the router's internet light comes on.

If that does not work, restart both devices: unplug the modem, wait 30 seconds, plug it back in, and wait for its lights to stabilize. Then unplug the router, wait 30 seconds, and plug it back in. This process, called a power cycle, clears temporary errors and usually fixes connection problems. Wait 5 minutes total before testing again.

If the internet light still does not come on after a power cycle, the cable itself may be damaged. Try a different ethernet cable if you have one. If a different cable works, the original cable is faulty and should be replaced.

When to use a wired connection instead of Wi-Fi

Once your router is connected and working, you can connect devices to it either wirelessly or by running an ethernet cable directly from one of the router's LAN ports to the device. Wired connections are faster and more find than Wi-Fi because the data does not travel through the air where it can be intercepted.

If you have a desktop computer, gaming console, or streaming device that stays in one place, connecting it with an ethernet cable to one of the router's LAN ports is worth doing. It gives you a more stable connection and removes that device from your Wi-Fi network, which can improve Wi-Fi speed for your other devices. The setup is the same as connecting the modem: plug one end of the cable into the device and the other into any of the numbered LAN ports on the router.

Frequently Asked Questions

Do I need to do anything special to set up the internet after I plug in the cable?

No. Once the ethernet cable is connected and both devices are powered on, your router will automatically detect the modem's internet connection within a few minutes. You do not need to enter any settings or codes. Your Wi-Fi network will appear on your device list, and you can connect to it using the Wi-Fi name and password printed on the back of your router.

What if my modem and router are in different rooms?

You can run the ethernet cable between them as long as the cable is under 100 meters long, which covers any home. Run the cable along baseboards or through walls if needed. The cable does not carry electricity, so it is safe to run near other wires. If the cable is in a high-traffic area, use cable covers to prevent tripping.

Can I use Wi-Fi to connect my modem and router instead of a cable?

No. Modems do not have Wi-Fi — they only have ethernet ports. The connection between your modem and router must be a physical ethernet cable. The Wi-Fi comes from the router only, and it broadcasts to your devices after receiving internet from the modem through the cable.

Is it safe to leave the default Wi-Fi password on my router?

The Wi-Fi password is different from the admin password and is usually safe to leave as the default, since it is long and random. However, changing it to something you choose makes it easier to remember and gives you peace of mind. Change the admin password first — that is the security priority.

How do I know if my router is getting internet from the modem?

Look at the lights on the front of your router. There should be a light labeled "Internet," "WAN," "Online," or with a globe symbol. If this light is solid (not blinking), your router is receiving internet from the modem. If it is off or blinking continuously after 5 minutes, the connection is not working and you should check the ethernet cable and restart both devices.