What’s the Difference Between a Cable Modem and Router?


Many High Speed Internet Service Providers (ISPs) boast about the numerous benefits of their service compared to dial-up. But rarely will they mention any of the potential consequences or dangers that come along with cable modems. This article will explain to you how a device called a ‘router’ (rhymes with ‘shouter’) can help keep your computer and its data safe from the Internet. Let’s discuss the differences between a cable modem and router.

Cable modems are wonderful devices. Once you’ve owned and installed a cable modem, you probably wondered how you ever lived without one. Your cable modem connects your computer to the digital world outside your home/office to the Internet. Your cable modem is always on and is ready whenever you are.  But without proper protection, you can easily become infected with viruses, worms and spyware that can easily access and manipulate your computer! In fact, your computer could be invaded or infected without you ever realizing it. Knowing the difference between a modem and router is important.

What does a modem and router do?

A router serves three purposes:

A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information.

A common misconception is that if you only have one computer, you don’t need a router. While you may not have a need for sharing your Internet connection, data or printers, a router provides security.

All routers act as hardware firewalls. Some routers have more intelligent firewalls than others, but any router is better than none. Windows XP/Vista has a built-in firewall as do many Internet security software packages. However, all software is prone to being manipulated, disabled or otherwise damaged. Many viruses are specifically designed to do just that. Once your firewall is down, your computer will become extremely vulnerable to all sorts of Internet baddies.

Spam email messages, identity theft and the further spreading of Internet worms and viruses are jobs most commonly done by infected computers whose owners don’t have a clue anything is wrong. Infected computers are referred to as “zombies.”

Avoid Becoming a Zombie

A router can often times look very similar to a cable modem. Both are small plastic boxes with lots of blinking lights. They can look very complex and intimidating, but in reality they are extremely easy to install and use. So easy, in fact, you might forget you have one.

Note: Most cable modems do not come with routers, while DSL modems usually have routers already built-in.

To determine if you are currently being protected with a router, simply follow these easy steps:

  1. Click Start in the lower left corner of your computer.
  2. Click Run.
  3. Type CMD and click OK.
  4. Type IPCONFIG.
  5. Press the Enter key on your keyboard.

You should see a prompt like “C:>Documents and Settings\User>”

Pay particular attention to your IP Address. If your IP Address starts with 192.168.xx.xx or if your IP Address starts with 10.0.0.xx then you generally are being protected by a router.

If your IP Address contains numbers other than those, it is highly recommended that you purchase and install a router immediately.

Type EXIT and press the Enter key on your keyboard to close this window.

Which Router Should I Buy?

Comcast Internet Router
A router is a device that forwards data packets between computer networks, creating an overlay internetwork. A router is connected to two or more data lines from different networks.

There are many routers to choose from and they will all do a decent job of protecting you. Routers that offer Stateful Packet Inspection (advertised with “SPI” in big letters on the box) have the more intelligent firewalls mentioned earlier.

Do not buy a wireless router unless you need the wireless functionality. You might find wireless routers available for less money then wired routers and be tempted to buy one to save money. Don’t!

Adding wireless to the equation means adding the need for securing that wireless and offers bad guys another door from which to access your computer. If you have a laptop or a computer that would benefit from having wireless, then by all means, purchase a wireless router. A wireless router does everything a wired router can do with the added capability of broadcasting your Internet connection throughout your home/office like a small radio station.

How to Install a Router

Installing a router is similar to installing a telephone answering machine. With the cable modem, router and your computer’s power off, unplug the cable modem from the back of your computer and plug it into the back of router where it is labeled WAN or Internet. The router will come with an extra network cable. Plug that network cable into any of the available ports on the back of the router;, the other end of that cable plugs back into your computer.

Then turn on your cable modem, turn on your router and turn on your PC. In most cases, your installation is complete and no software installation is necessary.

These steps are typical of most routers, but they are not meant to supersede or replace the instructions included with your router. Please refer to your router’s documentation for the manufacturers recommended installation instructions.

What a Router Won’t Do

A router can do a lot to protect you, but it can’t do everything. Your router can’t stop you from getting a virus, it can’t make your Internet go faster and it can’t do anything about the amount of junk email you receive.

The bad guys will try to grab control of your computer using a virus, a Windows exploit or a simple electronic open door. With active and constantly updated anti-virus software, applying all Windows updates from Microsoft and using a router, you’re  doing your best to block out invaders.

Hopefully, this article helped you figure out the difference between a modem and router!

Photo credit: Mr. T in DC via photo pin cc