How to Turn a Spare Computer Into a Super Powerful Router/Firewall


Most home/office routers/firewalls that people use have pretty pathetic hardware specs behind them. On the low end they can have as little as a 100mhz processor and 16MB of ram. On the high end they can contain around a 800mhz processor and 256MB of ram. I’m guessing you have a spare computer laying around with better specs than that. Also many routers/firewalls have poor interfaces, outdated software, security vulnerabilities, and are lacking all the features you want. Well, I’m going to change all that for you.

My favorite software to create a router/firewall and the one I personally use myself is PFSense. Look at all the features it has to offer.

The pfSense® project is a free, open source customized distribution of FreeBSD specifically tailored for use as a firewall and router that is entirely managed via web interface. In addition to being a powerful, flexible firewalling and routing platform, it includes a long list of related features and a package system allowing further expandability without adding bloat and potential security vulnerabilities to the base distribution. The pfSense project has become a fairly popular project with more than 1 million downloads since its inception, and proven in countless installations ranging from small home networks protecting a single computer to large corporations, universities and other organizations protecting thousands of network devices.

You will need a computer that has 2 ethernet ports to make this work. Basically an Input that will connect to your Modem and an Output that will either connect to a switch/hub or your computer. I suggest buying two PCI-E cards listed below if your computer can support it. PCI-E is faster, but PCI cards will work too.

Suggested PCI-E Network Card:
Suggested PCI Network Card:
PCI-E Card With Two Ports:

Here is the computer hardware PFSense suggests based on what speeds you want to achieve and features you will need.

Once your computer hardware is ready with two ethernet ports, you need to download the ISO from the following link, burn it to a disc, and boot from that disc to install PFSense.

Follow this installation guide to help you install PFSense:

There are numerous software alternatives, but my preference is PFSense with Smoothwall Express being a close second. Check out the links below if you want to see the other router/firewall alternatives besides PFSense. I’ve also heard good things about Sophos and Untangle, but have never personally used them.

Sophos UTM Home Edition
Untangle NG Firewall Free

Other Networking Advice
Now you are probably wondering how you are going to get wifi working and hook up all of your computers and devices. You are going to want to look into Access Points and Unmanaged Switches.

My favorite access points: Engenious ECB600 or Engenious ECB1750 or Ubiquiti Networks UniFi AC or SunSpot AC1200

Three reasonably priced switches: Cisco Gigabit 16 Port or Netgear Gigabit 16 Port or Netgear Gigabit 8 Port

My network setup looks like the following:
Cable Modem > PFSense Router/Firewal > 16 Port Gigabit Switch > ECB600 Access Point & Desktop Computers

4 Replies to “How to Turn a Spare Computer Into a Super Powerful Router/Firewall”

  1. TagCdog says:

    I was on a quest to find a router capable of handling my large data throughput. While I agree that PFSense is awesome and that if people are competent enough to get it running then they *should* be competent enough to manage it, I think it is too much for most consumer type people. I ran it on my home network just for fun (and for data throughput). Its obvious default state is to block everything until told otherwise. That means your VOIP wont work, your ATT uverse TV wont work (by the way, I spent three weeks and still couldn’t get it working), and everything else will need to be unblocked to get working. Additionally, a weak old computer can’t handle a large amount of traffic that well. End of story is I got an Ubiquiti Networks – EdgeRouter for ~$99 and it can handle enterprise class data transfer speeds (1M packets per second) while being very easy to use. I love PFSense but it is way too much for a home network and an old computer might not have enough specs to manage your interweb usage.

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