Why Do I Need a Firewall?
Unix/Linux is well known for its security and nobody doubts that. But why not work to make your machine even more secure. Securing your computer nowadays is very important and an absolute must. Or, do you want to be a little fish in the ocean? Sharks are hunting for fish like you and the big fish eats the little fish.
In order to stay secure and protect your privacy or data while you surf the web, you need some simple security skills. A very good point to start is the firewall.
What is a firewall?
Ok guys, a firewall can be a software or a piece of hardware, but what does it do and why do we need one?
Ok , you got a brain, right? Use it! Firewall is a word which can be split in to other words (fire + wall). I think that you understand. Not ye ? Hmm, let’s say that the firewall acts as a wall to protect your computer. Attackers will try to get access to your server by brute-force attacking your SSH account. But if you use a firewall you can set rules to block them. You can block specific IP’s to connect to your machine or you can block all IP’s expect your own.
Ok, but tell us more about this firewall. Why should I put time and effort to learn some basic firewalls?
For a newbie, it is hard to understand everything in a day or even in a month. Computer security is a very complex field. But, how about this. If I tell you guys what is going to happen to you and your machine if you don’t use a firewall (learn it by yourself or tell someone to set it up for you), are you going to understand why it is very important to have one? I think it will work fine, but let me see.
What is going to happen if i don’t use a firewall?
If you don’t have a firewall, it is a very high probability that someone, somewhere will find many open ports on your system or network. These open ports will allow him to brute-force your credentials, install malware and exploit software. Brute-force attacking your credentials means that an attacker is able to find your login credentials by trying many passwords at the same time. Attackers use GPU to try millions of combinations in a second, so it is so easy for them to find your FTP password. Scary! Do you want to block others from being able to view your open ports? Do you want to close some open ports that are a good target for an attacker to exploit and own your machine?
Even if you update your system it does not mean that it is going to be one hundred percent secure. Every system has its vulnerabilities. We’re not in a perfect world. Installing updates and especially security updates is very important, but it does not stop someone from trying to install a backdoor on your server, right? Or someone might try to install a remote computer controller program which monitors and records all your activities. Or a key-logger perhaps. So do you want your private data to be a public property?
There are many firewalls and ufw is a firewall which comes pre-installed in Ubuntu. This ufw has also a graphical version and it is very easy to use, so you will be happy to hear you can learn to protect your computer from attackers in my next article, even if you don’t know anything about security at all.
So guys, which is better in terms of security? A castle protected by walls, or a castle without walls around it? You can judge that.