With VPS benefits come risks and responsibility. Here’s how to protect your VPS with a security firewall that can filter all network traffic.

We all know that a virtual private server (VPS) offers benefits like faster loading speeds and more reliable performance compared to shared hosting. But as the old saying goes, great power comes with great responsibility. So if you’re going to host your website or company databases on a VPS, you need to make sure the server is well protected against cyberattacks.

As you probably know, a firewall is one of the simplest security devices available to system administrators. What you may not know is how a firewall works and what it does to protect your VPS and website from hackers or other threats.

Let’s find out.

What is a firewall?

The job of a firewall is to inspect and filter incoming and outgoing network traffic. Think of it as a border checkpoint that every single inbound or outbound data packet needs to go through. The firewall follows a set of rules and blocks any packets that don’t comply with them.

These rules are set in the firewall’s configuration files, and they mostly revolve around IP addresses, networking ports, and the type of traffic trying to pass through them. A firewall gives you numerous options for protecting your server.

Say, for example, that a specific IP address is known as a source of malicious traffic. A simple configuration setting is all you need to do to blacklist it and ensure that the person behind it can’t directly access your server. There are automated services that can do that for you, as well.

But blocking IPs is not the only thing a firewall does.

Traffic passes through networking ports. There are 65,535 ports, and every firewall must be configured to ensure that the applications and services installed on the server use the correct ones.

For example, SSH’s default networking port is port 22. However, your server’s firewall must block any attempts to establish an SSH connection to any other ports. So, a properly configured firewall should also close all unused ports.

How does a firewall protect my VPS, website and other data?

A firewall can be essential in many different scenarios. For example, you can use your firewall to block inbound traffic from certain countries. You can also restrict access to your website for specific IPs.

However, its primary role is to protect your website against Distributed Denial of Service (DDoS), brute-force attacks, and other online threats. But how does it do that exactly?

Well, the most basic security mechanism a firewall has is to block traffic from IPs that are sending an unusually high number of requests (e.g., junk traffic in the case of DDoS or failed login attempts in the case of brute-forcing attempts).

Unfortunately, modern attacks are pretty sophisticated. Cybercriminals utilize botnets – giant networks of thousands of compromised devices. This helps them cover their tracks more efficiently and makes the attacks much more powerful. It also means that blacklisting a single IP will do pretty much nothing to stop the hackers.

Firewalls have also grown much more complicated. They now take a closer look at the data packets they process and use more complex mechanisms to ensure that only legitimate ones make it through. Depending on these mechanisms, we can distinguish four different types of firewalls:

  • Packet filtering firewalls
    Packet filtering firewalls analyze individual data packets and use a set of criteria to determine whether they should be let through. These criteria include the source and destination IPs and the networking port.
  • Stateful inspection firewalls
    Stateful inspection firewalls employ more complicated mechanisms to identify traffic flow patterns and use them to distinguish between legitimate and malicious data. Some of them can also work on the network, transport, and application layers.
  • Proxy firewalls
    Proxy firewalls are similar to stateful inspection firewalls in that they use complicated mechanisms to determine whether or not a data packet is malicious. The difference is, they act as an intermediary between the outside world and your server, eliminating the direct connections from end users.
  • Next-generation firewalls
    Unlike conventional firewall systems that only inspect a data packet’s header, Next-generation firewalls also analyze the data within the packet. Some of them even come with anti-virus functionality and are much more effective at identifying and blocking malicious traffic.
How to set up a VPS firewall?

Since most web hosting servers use Linux, it’s probably best to focus on the firewall solutions for this platform.

Linux distributions usually come with either iptables or nftables – two IP packet filtering systems integrated into the Linux kernel. There are, however, many other solutions that either provide full-blown firewall functionality or use iptables or nftables as a framework and offer a wide range of additional features. Some of the names worth mentioning include ConfigServer Firewall (CSF), pfSense, Shorewall, and UFW.

Some of them are easier to use than others. For example, UFW gives you a Graphic User Interface (GUI) to set and manage firewall rules, while CSF offers cPanel integration. Which one you’ll choose depends on your needs and preferences.

The installation steps vary from firewall solution to firewall solution, but with all of them, you’ll need root access to set them up.

How can your hosting provider help?

Most of the firewall solutions listed above are pretty popular, and they come with extensive documentation, so it shouldn’t be too hard to find detailed information on what you need to do to install them.

That being said, the installation process usually involves executing some commands in the Terminal, and you also need to bear in mind that properly configuring the firewall requires knowledge of what sort of online threats you need to protect yourself against.

So if you think you’re not up for the job, don’t despair. You can let your hosting provider do all the heavy lifting for you.

If you opt for a managed VPS plan, your host’s experts will be responsible for setting up the virtual server and ensuring that it performs reliably and securely. This includes installing a firewall and configuring it.

The idea is that you can still reap the benefits of using a VPS rather than a less powerful shared solution, but you get to focus on your project, not on the complexities of server administration. If you have a specific set of requirements and need a custom setup, this probably isn’t the best solution. However, for the vast majority, a managed VPS is one of the best options for hosting a website.

Conclusion

Firewalls are absolutely essential for the security of your website and its data. In this day and age, you don’t necessarily need to set up and configure the firewall yourself. However, it really pays to know what it does and how it works.

Keep up with more on how to protect your VPS and related firewall tips by bookmarking and scrolling MobileVillage.com’s network security news and tips.