Why Firewalls are Important

In this video, we’re taking a look at why a firewall is important. If you’re not familiar with what a firewall is, a firewall is either a piece of hardware or a piece of software that sits between your computer and the internet. And the way it works is it has a set of rules that will determine whether traffic can flow from your computer to the internet or from the internet back to your computer, by either allowing or blocking that traffic. So when you go online, whether you’re surfing the internet, you’re playing online game, any communication between your computer and the internet, that needs to go through your firewall first.

And the firewall is going to look at that traffic and say either it’s allowed or not allowed to go through. That’s why this is a vital piece of software or, again, hardware. Because if a malicious piece of traffic is trying to get through– say someone puts a keylogger that’s going to send information back to the hacker’s computer– if your firewall’s properly configured and identifies that traffic, it’s going to block that traffic from getting back out again. Likewise, if there is something suspicious, it’s going to try to block that traffic. Or if you have a denial-of-service attack where someone is trying to flood your computer or your network, hopefully your firewall is going to block that traffic.

Now, most major software is going to have a firewall built in– operating systems, rather. OS X, Windows, Linux– they all have versions of firewalls built in. Likewise, there are hardware firewall out there. Things like Palo Alto has a firewall. It’s a physical piece of hardware. A lot of enterprise switches will have a firewall built in. Some network routers for homes will have a version of a firewall built in. And there’s also open source firewalls that you can buy, either using an old computer or a Raspberry Pi, you could use something like pfSense to create a hardware firewall. Now, let’s take a look at a firewall. We’re going to take a look at the Windows one.

And all firewalls are basically configured the same. So I’m going to type in “firewall” in the search bar here.

And we’re going to go into our firewall.

Now, in here I’m going to go through the “allow app” features. And as you can see here, these are the rules set in here. So these are the various services that are running on my computer. And we can see whether it’s allowed over a private network or a public network. And if it’s checked, that means it’s allowed. If I find something in here that I don’t want running through here, I could edit the details, change settings here, and I could either uncheck this– say, I don’t want Mixed Reality Portal running, I can uncheck this– and it will no longer run.

If it tries to go back out to the internet, or if the Mixed Reality Portal tries to come back in it’s going to block that traffic. So in general, you want to block traffic that doesn’t need to get through. So the more that you allow through, the more potential exposure you have to some malicious type of traffic. So firewalls will help prevent malicious program from getting onto your network. They also can prevent intruders from accessing your network through a series of rules. Between hardware and software, again, Windows, Linux, OS X will all have their built-in firewalls, but you can also buy firewall appliances. Hardware firewalls– most enterprise switches will have one built in.

Dedicated firewalls such as pfSense or Palo Alto firewalls exist. And they are recommended for larger networks, because they can handle quite a bit more traffic, and they generally have more granular rules that you can set up. Now, the rules of the firewall are organised through a series of rules which you’re going to have to spend some time with, especially if you’re on enterprise level, to configure to generally find an optimal balance between protection and functionality. If you have your rules too strict, then your users aren’t going to be able to do their day-to-day operations properly.

Hardware versus software: hardware firewalls tend to be better protection versus software. There’s less things that can tend to get around them, and less of a chance of a malicious program knocking out your firewall if it’s a hardware base. However, software firewalls are still better than no firewall at all. Now on enterprise level, this is generally where you’re going to consider the more strict rules. If you really need strict rules, if you really need to lock down your network, you may consider doing a rule of a “block all,” and then creating your allow list from there manually. Again, I wouldn’t recommend this for home use.

But on a very strict network, you may consider a “deny all,” then create your allow list. So this was about firewalls. And in the next video, we’re going to be talking about staying up-to-date with your driver updates. Thank you for watching. I’ll see you in the next video.