The basic connection: modem to router to devices

A modem receives internet from your service provider and converts it into a signal your devices can use. A router takes that signal and broadcasts it wirelessly to your home. To connect them, you plug an ethernet cable from the modem's ethernet port into the router's internet or WAN port, then power on the router and wait for it to boot.

The physical connection itself takes less than a minute. What takes longer is waiting for the router to recognize the modem's signal and assign itself an IP address — usually two to five minutes. During this time, the router's lights will blink as it initializes.

Key Takeaways

  • Connect an ethernet cable from your modem's ethernet port to your router's WAN or internet port — this is the only cable that matters for the connection to work.
  • Power on the router after plugging in the ethernet cable and wait three to five minutes for it to fully boot before testing your connection.
  • Check your router's lights: a solid or blinking internet light means the modem signal reached the router, while a dark light means the cable is loose or plugged into the wrong port.
  • You do not need to restart your modem when you add a new router, but restarting both devices in order (modem first, then router) fixes most connection problems.
  • The router's default username and password are printed on a sticker on the back or bottom of the device, and you should change them after your first login.

What cables and ports you need

You need one ethernet cable to connect the modem and router. This cable has a plastic connector on each end that clicks into place. Most routers come with one ethernet cable in the box; if yours did not, any standard ethernet cable works — they are inexpensive and sold at any electronics store.

On the modem, find the port labeled ethernet or LAN. On the router, find the port labeled WAN, internet, or uplink — it is usually a different color from the other ethernet ports and often sits apart from them. Plug one end of the cable into the modem's ethernet port and the other end into the router's WAN port. The connector should click audibly when it seats properly.

Do not plug the ethernet cable into one of the router's regular LAN ports by mistake. Those ports are for connecting devices like computers or printers directly to the router. Only the WAN port receives the signal from the modem.

Powering on and waiting for the router to boot

Plug the router's power cable into an outlet. The router will take two to five minutes to fully start up. During this time, you will see lights on the front of the router blink or change color. Do not unplug it or restart it during this process.

Watch for a light labeled internet, WAN, or online. When this light turns solid or blinks steadily, the router has recognized the modem's signal. If this light stays dark or off after five minutes, the ethernet cable is either loose, unplugged, or plugged into the wrong port on the router — unplug it and try again.

Once the internet light is on, the router is ready to use. You can now connect your devices to the router's wireless network or plug them in with ethernet cables.

Finding and changing the router's default password

Before you connect devices, you should change the router's default username and password. These are printed on a sticker on the back or bottom of the router. Write them down before you proceed.

Open a web browser on any device connected to the router and type the router's IP address into the address bar. This address is also on the sticker — it usually looks like 192.168.1.1 or 192.168.0.1. Press Enter and log in using the default username and password from the sticker.

Once you are logged in, look for a section called settings, administration, or security. Find the option to change the password and create a new one. Write this new password down and keep it somewhere safe. You will need it if you ever need to log back into the router.

Testing your connection

After the router has booted and you have changed the password, open a web browser and try to load a website. If the page loads, your modem and router are connected and working. If the page does not load or times out, restart both devices in this 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.

If restarting does not fix the problem, check that the ethernet cable is firmly clicked into both the modem and the router. A loose connection is the most common reason a newly connected router does not work.

What to do if the router does not recognize the modem

If the router's internet light stays dark after five minutes, the modem signal is not reaching the router. First, unplug the ethernet cable from both devices and plug it back in, making sure you hear a click on each end. If the light still does not turn on, try a different ethernet cable — the first one may be damaged.

If a different cable does not help, check that you plugged the cable into the router's WAN port, not one of its LAN ports. The WAN port is usually labeled clearly and often sits to the left or right of the other ports. If you plugged it into a LAN port by mistake, move the cable to the WAN port and wait another minute for the light to turn on.

If the light still does not turn on after trying a new cable and confirming the correct port, restart the modem by unplugging it for 30 seconds, plugging it back in, and waiting for its lights to stabilize before powering on the router again.

Frequently Asked Questions

Do I need to restart my modem when I connect a new router?

No. The modem does not need to restart when you add a router. However, if the router does not recognize the modem's signal after five minutes, restarting the modem often fixes the problem. Always restart the modem first, wait for its lights to stabilize, then restart the router.

Can I use any ethernet cable to connect the modem and router?

Yes. Any standard ethernet cable works, regardless of length or brand. Longer cables do not slow down your connection. If your router came with a cable in the box, use that one first. If it does not work, try a different cable — a damaged cable is sometimes the problem.

What if my router has no WAN port?

Some mesh routers and older models do not have a separate WAN port. Check your router's manual to see which port receives the modem signal. If the manual is not available, contact the router's manufacturer or look up the model number on their website.

Why is my internet light on but I still cannot connect to the internet?

The internet light means the router recognizes the modem, but it does not may provide your devices can reach the internet. Restart both the modem and router in order, then try connecting a device again. If that does not work, check that you are connecting to the correct wireless network name — it is printed on the router's sticker.

Can I use WiFi before I change the router's default password?

Yes, but you should change the password as soon as possible. Until you do, anyone within range of your router can connect to your network and use your internet. Changing the password takes five minutes and protects your connection from unauthorized use.