Do You Need a Router If You Have a Modem?

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In a home network, it is your modem that allows you to connect to the internet via your internet service provider, so what is the purpose of the router, and do you need one if you already have a modem?

A router is not required to access the internet, however, only one wired device will be able to connect to the modem and access the internet. Not having a router presents major security concerns as the public IP address will resolve directly to the device, leaving it exposed on the internet.

In this article, we’ll look at whether you really need a router if you only have one device that needs access to the internet, and how the router can actually be considered the most important part of your home network for security.

Do You Need a Router If You Only Have One Computer?

It is certainly possible to plug a computer directly into your modem and start browsing the internet, however, I would compare this to riding a bike at night without the use of any lights.

You are still able to ride your bike and get to your destination, but it really isn’t recommended.

When your computer is connected directly to your modem, it is in turn connected directly to your internet service provider (ISP) and from there, the internet.

Connectivity-wise, there is nothing wrong with this setup; you will be able to browse the Internet as you would normally expect to be able to.

The issue, which I personally consider to be quite a major one, is from a security standpoint.

Consider your modem to be a simple data transfer device. Unlike a router, it has zero security features.

In my opinion, this is the number one reason to always be making use of a router in a home network set up.

You may also like: How Does a Router and Modem Work Together?

Will a Network Switch Work With a Modem?

If a single computer can get an internet connection when connected directly to the modem, why not plug in a switch instead? That way multiple devices plugged into the switch can get an internet connection at the same time, surely?

All devices should be able to communicate with each other and be able to access the internet, however, the security concerns we described above still apply. You will just have even more devices exposed over the Internet!

In addition to this, your ISP will only provide you with a limited number of public IP addresses.

Often this is a single IP address, but you may get two or three if you are lucky.

Once your ISP has reached the maximum number of IP addresses it can give, it will simply stop and any additional devices will not receive one and won’t be able to communicate on the network.

For this reason, connecting a switch directly to the modem really is a complete waste of time.

In some circumstances when there are no available public IP addresses, your device will receive an APIPA address (169.254.x.x) when it attempts to join the network

This still prevents it from communicating with other devices on the network and being able to access the internet., so won’t really benefit you in any way.

The bottom line is that having devices connected to a switch that in turn is connected directly to a modem is an even worse setup given that more than one device is exposed on the internet.

What Are the Risks of Connecting Directly to Your Modem?

With your computer connected directly to your modem, it will be completely exposed out on the internet.

The IP address that is assigned to your modem, which is known as your public IP address, will resolve directly to your computer.

This means that any vulnerabilities on your computer, be it a vulnerability in the operating system or a port being left open, are potentially accessible to anyone that knows your public IP address.

Now you may be thinking: With the massive amounts of public IP addresses out there, what are the chances that cybercriminals will target me? It would be pretty unlikely.

True, however, it isn’t worth the risk when you consider that these criminals work tirelessly to find compromised devices and perform malicious activities on them. 

It has got so bad that they are now using automated tools to look for, access, and infect vulnerable devices around the clock, without even needing to press a single key on their keyboard.

When your computer is connected directly to your modem, you are relying 100% on the computer itself for any protection whatsoever. This could be protection coded into the operating system itself or a piece of installed firewall software.

These, unfortunately, have found to not be very effective at protecting against cybercriminals.

The word often spreads quickly when a cybercriminal is able to find a way around the computer’s built-in protection, making a computer connected directly to a modem even more vulnerable.

Why Should You Use a Router?

The recommended set up is to connect a router to your modem instead.

Even if you only have one device to connect to your network (which is very unlikely these days) a router is still an incredibly important part of the network that shouldn’t be overlooked.

A router is a device that forwards packets of data along at least two different networks.

Most commonly, one network would be your ISP and the other would be your home network.

Routers keep track of which device on your network makes a request to the internet and ensures responses are sent back to that device only.

Not only will the router provide many devices with a connection at the same time, but it also comes with a firewall built-in that is much more capable than the firewall you will have built-in to your operating system, or even the third-party software that you may even have to pay for.

Related article: Best Place for a Router: 8 Tips

What If Your ISP Only Provides a Router?

It isn’t uncommon for your ISP to provide a single device when you sign up with them.

A common misconception is that the single device they send you is a router, but as you now know, a router without a modem is useless.

It is the modem that connects to your ISP and from there, the internet.

The device that they actually send you is more likely to be a modem with a router built into it.

A two in one solution (modem and router) is common, but a three in one solution (modem, router and wireless access point) is even more commonly found.

In that, you could even consider these units to be a switch as well given they often have several ethernet ports on the back for connecting devices directly using an ethernet cable.

Don’t worry if your ISP only sends you the one device in the mail when you sign up with them; it is very likely to have at least the modem and router contained within the single unit.

If in any doubt, contact your ISP who will be able to explain what they have sent you and how to get everything hooked up.

Final Thoughts

Do you need a router if you have a modem?

Technically, no,. You can plug a computer into the back of the modem and be able to freely browse the internet.

This does present you with a host of security issues, though, with the computer being visible to anyone that knows your public IP address.

The recommendation is to instead connect a router to your modem.

This not only allows multiple devices to be connected at once but also offers much better protection and security thanks to the built-in firewall and it being able to hide the IP address of each device from anything that is not connected securely to your network.

It is simply an unnecessary risk to not be using a router at home.