WTF is a Firewall?
If you own a computer, you’ve probably wrangled with firewalls. You might have received an error message about Windows Firewall blocking a program. It’s also possible you had a program on your computer that needed to access your network’s firewall to keep connecting to the internet.
A Firewall is a cryptic, ethereal presence in all our lives, but if you can think of it as a wall between you and the internet, you’re halfway there.
Well, the short answer is security. Having a firewall protects you from attacks. Without a firewall, a hacker could theoretically access the information on your computer or network with a few simple keystrokes. All they would need is your IP address, and that is really easy to get. When you visit a website for example, that website logs your IP address and the webmaster can track that IP address using free tools available all over the internet. In most cases, your firewall is your first round of defense against attacks.
Firewalls have holes in them to let traffic through. Those holes are called ports. Theoretically, your firewall would come with all incoming ports closed. That means that no programs, computers, services or people can access your network, without being physically there. Picture Wile E. Coyote running into the painting of a tunnel.
You can open those ports using your firewall settings but it is more complicated than it sounds. There are a few things to keep in mind.
You can setup port forwarding on your firewall to allow traffic through. All services use their own protocol for port forwarding. But the premise is simple and is best illustrated using an example:
I want to setup an open port, so I can remote into my computer at home. I go to port forwarding in the firewall section of my router’s menu and tell the router that I want anyone who asks to use remote desktop on my network to automatically be forwarded to my personal desktop using the ip address of my personal desktop.
There may be a few firewalls on your network blocking traffic. Your computer has a firewall. In fact, all Windows PCs are shipped with a firewall installed and activated. Your router and your modem probably both have a firewall. So, when you are opening ports and forwarding them to an ip address on your network, remember, you may have to setup port forwards on multiple devices.
In this case, when you set up port forwarding you may have to daisy chain the port forwards, like so:
If you don’t want to spend all your time setting up daisy chained port forwards and hoping they work, you can setup a DMZ. DMZ stands for demilitarized zone. It’s super helpful when you are trying to setup port forwarding and you’re dealing with multiple firewalls. It tells your Modem’s firewall that any traffic coming in is automatically forwarded to the IP address of the router and then your router’s firewall has to do all the work.
Founder and CEO of Priority IT Works
Jami has 6+ years of Information Technology experience. He received his degree in Business Economics and has a strong background in the service industry. Jami believes in combining the Information Technology industry and the Service industry in order to make his team’s services more accessible to the client.