Connect the modem first, then the router to it

Your modem and router are two separate devices that work together. The modem connects to your internet service provider's line (cable, fiber, or phone line depending on your provider). The router takes that connection and broadcasts it wirelessly throughout your home. You must connect them in a specific order, or neither will work.

The physical setup takes about five minutes. The tricky part is knowing which cables go where and understanding why the order matters. Most people plug things in backwards and then spend an hour troubleshooting when the real problem is the sequence.

Key Takeaways

  • Your modem connects directly to the wall outlet or cable box; your router connects to the modem, not to the wall.
  • Always power on the modem first and wait for its lights to stabilize before powering on the router.
  • The cable from the wall goes into the modem's port labeled "Cable In" or "Internet In", never into the router.
  • Use an Ethernet cable to connect the modem's "Internet Out" or "LAN" port to the router's "Internet In" or "WAN" port.
  • If lights don't stabilize within two minutes, the modem may not have synced with your provider yet — wait up to ten minutes before assuming something is wrong.

Gather the cables and devices you need

Before you plug anything in, make sure you have the right equipment. You need the modem your internet provider gave you (or that you purchased), a separate router, a coaxial cable (the thick cable with the threaded connector) if you have cable internet, and an Ethernet cable — the thin cable with plastic connectors on both ends that looks like a phone cord but wider.

If your provider gave you a combined modem-router unit, you do not need a separate router. Those all-in-one devices handle both jobs. But if you have two separate boxes, keep reading. The Ethernet cable usually comes with the router. If it did not, any standard Ethernet cable works; they are inexpensive and available at any electronics store.

Connect the modem to the wall outlet

Locate the cable, fiber, or phone line coming into your home. This is usually in a basement, closet, or garage. The cable from the wall has a connector on the end — either a threaded coaxial connector (looks like a thick screw) or a fiber connector (looks like a small plastic clip).

Unscrew or unclip the old cable if something was already connected there. Screw or clip the cable into the port on the modem labeled "Cable In," "Internet In," or sometimes just "In." Hand-tighten only — do not use pliers. If you have fiber internet, the connector clicks in; if you have cable, it screws in. The modem should have exactly one port that matches your cable type.

Power on the modem and wait for it to stabilize

Plug the modem's power cable into an outlet and press the power button if it has one. Look at the lights on the front of the modem. You will see several lights, usually labeled or color-coded. The exact lights vary by modem model, but you are looking for the ones labeled "Power," "Internet," "Online," or "Downstream" to turn on and stop blinking.

This process takes one to three minutes for most modems. During this time, the modem is communicating with your internet provider's network to confirm your account and sync the connection. Do not unplug it or move on yet. If the lights are still blinking rapidly after five minutes, wait another five minutes. Some modems take up to ten minutes on the first power-on. If the lights do not stabilize after ten minutes, the modem may not be getting a signal from the wall — check that the cable is hand-tight and fully seated.

Connect the router to the modem with an Ethernet cable

Once the modem's lights have stabilized, take an Ethernet cable and plug one end into the modem's port labeled "Internet Out," "LAN," or "Ethernet." This is usually a different port from the one where the wall cable plugged in. Most modems have only one or two Ethernet ports, so it should be obvious which one to use.

Plug the other end of the Ethernet cable into the router's port labeled "Internet In," "WAN," or "Uplink." The router will have multiple Ethernet ports — the WAN port is usually a different color (often yellow or blue) or labeled separately from the other ports. Do not plug the Ethernet cable into one of the regular LAN ports on the router; it will not work. The cable clicks in when it is seated correctly.

Power on the router and wait for its lights

Plug the router's power cable into an outlet and press the power button if it has one. The router's lights will begin blinking. You are waiting for the light labeled "Internet," "Online," "WAN," or the light next to the WAN port to turn solid or stop blinking rapidly. This usually takes one to three minutes.

While you wait, you may see other lights turn on — these represent the wireless network and the other Ethernet ports. The important one is the internet light. Once it is solid, your router is connected to the modem and receiving internet. You can now search for the router's wireless network name on your phone or computer and connect to it using the password printed on the router's label.

Troubleshoot if the router's internet light does not turn on

If the router's internet light stays off or blinks red after three minutes, the connection between the modem and router is not working. First, check that the Ethernet cable is fully clicked into both the modem and the router. Unplug it from both ends and plug it back in firmly. Sometimes a cable looks seated but is not.

If the cable is seated and the light still does not turn on, try a different Ethernet cable if you have one. Ethernet cables can fail, and a bad cable is more common than a bad port. If a different cable works, the original cable is faulty. If the light still does not turn on with a new cable, the modem or router may have a hardware problem — contact your internet provider about the modem, or the router manufacturer about the router.

Frequently Asked Questions

Can I plug the wall cable directly into the router instead of the modem?

No. The modem is the device that converts the signal from your internet provider into a form your router can use. If you plug the cable directly into the router, nothing will work. The modem must sit between the wall and the router.

Do I need to restart the modem and router after connecting them?

Not usually. Once both devices are powered on and their lights are stable, they should work. If you experience problems later, restarting both (power off, wait ten seconds, power on) often fixes temporary glitches. Always restart the modem first, wait for its lights to stabilize, then restart the router.

What if I have a combined modem-router unit?

You only need to plug the wall cable into the "Internet In" port and power it on. There is no separate router to connect. Wait for the lights to stabilize, then search for the wireless network on your phone or computer.

Can I use WiFi instead of an Ethernet cable to connect the modem and router?

No. The modem and router must be connected by a physical Ethernet cable. WiFi is for connecting your devices (phones, laptops, tablets) to the router, not for connecting the router to the modem.

How far apart can the modem and router be?

The Ethernet cable can be up to 100 meters long, but practically, keep them within 30 feet if possible. Longer cables can sometimes cause connection issues. The router broadcasts WiFi throughout your home from wherever it sits, so you do not need to place it near the modem once they are connected.