Firewalls are your first line of defense against online threats, but is Windows Defender Firewall up to the task alone? Find out when it’s enough—and when you may need backup.

What Is a Firewall, and How Does It Work?

Firewalls are a security barrier between trusted internal and external networks, such as the Internet. It’s usually part of a security system that monitors and filters incoming and outgoing network traffic based on set security rules. Network traffic flows when you are connected to an external network, and this traffic contains data packets which is what the firewall inspects and filters. As Microsoft states, the default behavior of Windows Defender Firewall is to block all incoming traffic unless solicited or matching a rule, or to allow all outgoing traffic unless matching a rule.

Firewalls can be software, hardware, or even a combination of both. There are several types of firewalls. However, in a basic sense, there is an allow list and block list (formerly referred to as “white list” and “black list”), where networks, IP addresses, domains, and applications are added to either list, to either allow access to the resource or deny it. However, not only do they monitor and filter the traffic, but they also log the traffic and all security events for a period.

What if You Had No Firewall?

Windows Defender Firewall protects your Windows system from network-based threats, such as Denial-of-Service (DoS) attacks, malware, and more. Since they act as gatekeepers, a firewall can block unauthorized users and potential hackers from accessing private networks.

If you have no firewall, it can lead to a hacker gaining access to your system and private and confidential data, and leaves room for various strains of malware to infect your machine, including viruses, worms, and even ransomware. Firewalls also play an essential role in maintaining data privacy by controlling what information can enter or leave a network, which can protect against data theft.

Windows Firewall is enabled by default and should still be enabled unless you’ve disabled it manually or installed a third-party firewall.

To check if your Windows Defender Firewall is connected, click the Windows start menu (or press the keys Windows+i), and search Firewall:

Press Enter and a window will appear:

If Windows Defender Firewall is connected, it should say “Connected” as shown above. However, if it’s not connected, click “Use Recommended Settings” to turn it on.

Is Windows Defender Firewall Enough?

Windows Defender Firewall is sufficient for the average internet user, and for the most part, no additional firewalls are required. It has a minimal impact on system performance and Microsoft frequently updates it to address new threats. Since it was developed by Microsoft, it seamlessly integrates with the Windows operating system. It’s user-friendly compared to a lot of other firewalls and it doesn’t require extensive configuration.

Windows Defender Firewall includes an interface with advanced firewall configuration where you can create advanced firewall rules. This is accessible through the Windows Defender Firewall with Advanced Security interface.

Advanced features of a firewall allow you to easily control which applications you allow to connect to the Internet. You can create custom rules that block certain programs from connecting to the Internet or only allow a program to communicate with a specific IP address. When a program initiates an outgoing connection, it triggers a pop-up window, and you can choose to grant or deny access from connecting to the Internet.

It can become a little tiresome as sometimes there are multiple requests from one application connection that can trigger multiple pop-up windows. However, it does give you more power and control as a user. If you want a bit more control without having to use a third-party firewall, fortunately, Windows Defender Firewall actually offers more features than you might expect.

However, a firewall is just one aspect of security, and there are other avenues for a hacker to access or launch an attack. It’s important to always update your Windows computer, and be aware of common online scams that are on the rise.

But Who May Need an Additional Firewall?

For the average Windows user who primarily browses, games, and shops online, Windows Defender Firewall is sufficient, as long as you use Windows Security along with it, and follow good security practices. On the other hand, remote workers and those traveling that handle sensitive corporate data may benefit from an additional firewall.

Many Fortune 500 companies use Windows Security, but they also benefit from additional firewalls, as do small and medium businesses (SMBs). Firewalls are also required for compliance to help organizations meet regulatory requirements for data protection and network security. Additional firewalls are good for businesses, as they not only protect a business against data breaches and theft, but they can also improve employee productivity by blocking access to non-work-related websites and reducing the risk of reputational damage done by security incidents.

One of the biggest differences between Windows Security and a more advanced firewall, such as Next-Generation Firewall (NGFW), is that it can be used for threat detection as it can monitor, identify, and alert administrators to potential security threats, which is particularly useful for security teams. NGFWs can also perform proactive actions like intrusion prevention and application control.

Firewalls also work well with VPNs and facilitate secure remote access where the VPN encrypts the user’s IP address and data through a secure tunnel, and the firewall filters the traffic. It provides another layer of security, allowing safer connections for remote workers.

In the end, Windows Defender Firewall does the job for most—but a little extra security never hurts.