What Is a Virtual Firewall and How Can It Protect Your Cloud Resources?

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Protect your cloud assets!

As time goes on, more and more companies are leaping to the cloud. However, you’ll need to protect your cloud assets from cyberattacks—so how can you do this? Your answer is to use a firewall that’s especially suited and adapted to a virtualized environment. In short, a virtual firewall is your solution.

In this article, I’ll explain what virtual firewalls are, how they work, and their use cases. I’ll also compare them with traditional firewalls and give you a list of the top 3 firewall providers on the market today.

As always, let’s begin with a simple definition!

What Is a Virtual Firewall?

A virtual firewall protects cloud applications and infrastructure, such as virtual machines (VMs). This firewall is similar to a traditional firewall in several aspects. However, unlike a traditional firewall, you deploy a virtual firewall as software or as Software as a Service (SaaS).

While you use traditional firewalls to protect physical computers and servers, you’d typically use a virtual firewall to protect your virtual assets. 

Let’s explore how virtual firewalls work next.

How Virtual Firewalls Work

Like a traditional firewall, a virtual firewall inspects incoming data packets for any unauthorized material. It also controls the incoming and outgoing traffic in partnership with servers and switches. However, unlike a traditional firewall, a virtual firewall can operate in 2 modes:

1. Hypervisor Mode

If you’ve worked with VMs before, you should be familiar with the term “hypervisor”. In essence, this is a part of a VM that handles the connection between the host computer’s resources and the virtual machines that reside on that host. In the context of this article, a virtual firewall operates in isolation from the physical network. Simply put, the virtual firewall lives in the host CPU kernel and will control the traffic coming in and out of the VMs.

2. Bridge Mode

In bridge mode, a virtual firewall acts like a traditional firewall. Specifically, it’ll monitor and diagnose incoming and outgoing traffic in all VMs. 

Now that you know how virtual firewalls work, let’s look at their use cases.

Virtual Firewall Use Cases

You can use virtual firewalls for many things. In this section, I’ll touch upon the top 3 use cases for these firewalls.

1. Data Filtering

A virtual firewall can secure assets and networks by filtering and controlling the traffic that passes to and from the internet onto virtual cloud networks. This is basically the firewall’s primary function

2. Data Replication

Concerning virtual firewalls, you can secure a physical data center by extending it to the cloud. This is useful when migrating applications to the cloud that require connections to physical data centers. 

3. Virtual Network Protection

You can use a virtual firewall to replicate the same security traditional firewalls use to protect your virtual networks.

So far, I’ve lightly touched upon traditional firewalls in the article. It’s time to discover how virtual firewalls stack up against their traditional counterparts.

Traditional Firewalls vs Virtual Firewalls

Traditional firewalls and virtual firewalls have several similarities and differences. This section seeks to educate you on how they stack up against each other. Let’s start with traditional firewalls.

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Will you stay traditional, or will you go virtual?

Traditional Firewalls

A traditional or physical firewall connects your network to the internet. You typically use these firewalls for everyday network security and protection. Let’s take a look at their pros and cons.


  • Reduces threats significantly because a traditional firewall rests between your network and the internet; all traffic must pass through it
  • Has overall faster response times and can handle heavier loads
  • Gives you complete control over your firewall’s configuration and operations


  • Can be time-consuming: you need to physically set up and configure a traditional firewall, as well as integrate it with other components of your network
  • Is much more expensive than software
  • Requires IT and support staff for setup, configuration, and maintenance purposes

Next up, virtual firewalls!

Virtual Firewalls

As mentioned before, a virtual firewall is software that runs inside virtual environments. These firewalls pass traffic through virtual switches and other VMs. They’re similar to traditional firewalls but don’t have the hardware or maintenance overheads. Let’s look at their pros and cons.


  • Have easier configuration and faster setup
  • Are much cheaper to purchase and maintain
  • Help prevent cyberattacks because they’re centrally administered


  • Are in the same location as the system they’re trying to protect
  • Slow down VM performance in the long run
  • Can be bad for you if you have a public IP address

Those are the pros and cons of both types of firewalls. What do you think? The most important thing you need to ask yourself is: “What will I need my firewall to do?” Consider your business’s needs and requirements before making any decision.

That said, it’s time to look at the top virtual firewalls on the market today.

Top 3 Virtual Firewalls 

In this section, I’ll review 3 virtual firewalls you can use for your company that offer a high level of protection, along with some other features. Let’s start with GFI KerioControl.

GFI KerioControl 

GFI KerioControl is a next-generation firewall that can manage threats for small and medium-sized businesses. It’s a good option if you’re looking for an all-in-one security package. Here are some of its features:

  • Firewall and router that safely connects you to the internet
  • Intrusion protection system (IPS) that monitors traffic
  • Web content and application filtering
  • VPN

All in all, you can use KerioControl as a software application, virtual machine, or as a hardware firewall.

Barracuda CloudGen Firewall

The Barracuda CloudGen Firewall is also a next-generation firewall that has great scalability. This means that it can work with any business regardless of its size. Here are some of its features:

  • Multi-Factor Authentication (MFA)
  • Malware protection
  • Botnet and spyware protection
  • Denial-of-Service (DoS) and Distributed Denial-of-Service (DDoS) protection

Barracuda CloudGen Firewall has plenty of advanced features and functions that can help make monitoring and protecting your network easier.

Arctic Wolf Virtual Firewall

Arctic Wolf is a Firewall as a Service (FWaaS) that can offer your company 24/7 protection. One advantage of using this firewall is that you don’t need to spend your resources on maintaining it because it comes to you as a service. Here are some of its features:

  • Managed detection and response for 24/7 security protection
  • Identifies and stops threats across SaaS resources
  • Cloud analytics to detect threats using machine learning (ML)
  • Broad visibility into your networks

Let’s have a quick recap now.

Final Words

If your company is doing anything in the cloud, I highly recommend that you use a firewall that protects your virtual networks and your cloud-based infrastructure. A virtual firewall has loads of benefits, such as being less costly and less complicated to set up than a traditional firewall. 

You have several options available to you in the market, such as GFI KerioControl. Overall, as more and more IT applications move online, the need for more specialized security increases and becomes a necessity.

Do you have more questions about virtual firewalls? Check out the FAQ and Resources sections below!


How many types of firewalls do you have in the IT world?

You might be very surprised to learn that the answer is 8! Yes, you have 8 different types of firewalls out there. Each one’s primary goal is to protect your network, and they all have their own nuanced ways of doing that. Furthermore, they each have their own advantages and disadvantages, depending on your business’s needs.

What is the main difference between virtual and traditional firewalls?

A virtual firewall is data-centric and will protect your network by leveraging features such as multi-factor authentication (MFA) and encryption. On the other hand, a traditional firewall is hardware used to secure your network. You can find more information on their differences in this article.

Are firewalls required for every business?

If you’re connected to the internet, you need a firewall. A firewall helps protect your business from cyberattacks such as malware and DDoS attacks. Firewalls also help you in complying with security standards such as ISO 27001. Also, remember that it’s not just about protecting your networks but also your customer’s stored data on those networks.

What is a DDoS attack?

A Distributed Denial-of-Service attack, or DDoS attack, is a network-based attack designed to overload your resources and subsequently take down your systems. These attacks can slow your network and prevent your customers from connecting to your website. A virtual firewall can help prevent DDoS attacks in the first place.

Do firewalls prevent cyberattacks?

Yes, they do, to an extent. However, you’ll need to have other security measures in place for the best protection. As mentioned above, firewalls can prevent DDoS attacks and other cyberattacks, such as ransomware and malware. That said, you’ll need more than just a firewall to get the most comprehensive protection. An intrusion prevention system (IPS) on top of your firewall can work wonders.


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