How To Connect A Modem To A Computer Without a Router

In this article we’re going to cover how to connect a computer (PC/laptop) directly to a modem, without needing to use a router. This is actually possible, though only by cable, and one connection only.

Here are the quick steps:

  1. Get an RJ-45 ethernet cable
  2. Plus one end into the ethernet port on the computer
  3. Plug the other end into the modem ethernet port.
  4. The computer and modem are now connected.
  5. Modems can provide one wired LAN connection.

Now let’s go through these steps in illustrated form.

How To Connect a Computer To A Modem Directly

Step 1 – Grab a standard RJ-45 Ethernet cable (also known as a LAN/network cable). It looks like this:

Ethernet Cable

Click the links to get 5m and 10m ethernet cables from Amazon if you need one.

Step 2 – Plug one end into the ethernet port on your computer (PC/laptop):

On laptops, it’s often on the side; on PCs, it’s usually on the back of the tower.

Step 3 – Plug the other end of the ethernet cable directly into the ethernet port (not the RJ-11 port that goes into the phone line) on the modem. Modems have one ethernet port, which is meant to connect it to a router. However, you can plug a device in directly if you want.

Your modem and computer are now fully connected, and as long as you have a live and activated internet service, and the modem is hooked up to the phone line/master socket with an RJ-11 cable, you should be able to browse online freely with that device!

The Limitations Of Using Just a Modem

However, running through this process of connecting a modem to a PC/laptop directly, we start to see why Wi-Fi routers exist to complement modems, and what their main function is.

It is true that just using a modem, you can connect a single device up to it by LAN cable, as we showed above.

However, there are a few huge caveats to this:

  1. That’s ALL you can connect up; just that one device through that one ethernet port. You can’t connect any more devices.
  2. Modems offer no Wi-Fi functionality at all. You can connect one device by ethernet only. Modems do not broadcast Wi-Fi networks like routers do.
  3. There’s often no security when connecting straight up via the modem. No fire-walling or other security measures that a router provides.

In very rare cases, a modem might have two ethernet ports, which provides a little more access, but mostly it’s just one port on the back.

This leaves you pretty limited on any home network with more than one device.

Imagine having to take turns to plug devices into the one and only port on the back of a modem to access the internet, while the next people queue up and wait for you to be finished so they can check their emails! And users on Wi-Fi couldn’t connect to the modem at all, since it doesn’t have wireless functionality.

This wouldn’t really be any good, so we start to see why routers exist. You are ideally meant to hook this up to the modem via cable, and then connect devices to this router instead, to provide more options. Wi-Fi routers have multiple ethernet ports (usually 4), plus they emit one or more Wi-Fi networks to connect to. They essentially allow for the efficient management of a home network.

Related Articles

Here are links to some more articles which explore the interrelations and inter-dependency between modems and routers:


Online gamer and general home networking enthusiast. I like to create articles to help people solve common home networking problems.

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