10 Host-Based Firewall Best Practices

A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. A firewall typically establishes a barrier between a trusted internal network and an untrusted external network, such as the Internet.

Host-based firewalls are deployed on individual hosts and provide protection for those specific systems. In this article, we will discuss 10 host-based firewall best practices that can help you secure your systems.

1. Enable the firewall

A firewall provides a critical layer of security for your systems and networks. By default, most firewalls are turned off. This leaves your systems and data vulnerable to attack.

When you enable a firewall, you’re essentially telling the firewall to start filtering traffic. The firewall will allow or deny traffic based on a set of rules. These rules can be based on things like IP addresses, ports, and protocols.

Enabling a firewall is one of the simplest and most effective ways to improve your security posture. It’s a best practice that every organization should follow.

2. Block all incoming connections by default

When a firewall is first installed, it’s typically set to allow all traffic by default. That means that any malicious traffic that manages to get past your network-based firewall will have an open door into your systems.

By contrast, if you block all incoming traffic by default, any traffic that does manage to get past your network firewall will be stopped at the host level. That gives you an extra layer of protection and makes it much more difficult for attackers to gain access to your systems.

Of course, blocking all incoming traffic can make it difficult to allow legitimate traffic through, so you’ll need to carefully configure your firewall rules to allow the traffic you need while still blocking everything else. But the extra effort is worth it for the added security.

3. Allow only authorized applications to connect outbound

If you allow all outbound traffic, then an attacker can use your host as a pivot point to attack other systems. By only allowing authorized applications to connect outbound, you can help prevent attackers from using your host to attack other systems.

Additionally, by only allowing authorized applications to connect outbound, you can help reduce the chances of data leakage. For example, if you allow all outbound traffic, then an attacker could exfiltrate data by connecting to an FTP server. However, if you only allow authorized applications to connect outbound, then the attacker would not be able to exfiltrate data via FTP.

Finally, by only allowing authorized applications to connect outbound, you can help improve performance and reduce costs. For example, if you allow all outbound traffic, then your host will need to process all outgoing traffic, which can consume resources and impact performance. However, if you only allow authorized applications to connect outbound, then your host will only need to process traffic for those applications, which can help improve performance.

4. Configure your firewall for each network location type

When you connect to a new network, your computer will automatically assign that network a location type. The location type will determine which firewall rules are applied.

If you don’t configure your firewall for each network location type, your computer will use the same firewall rules for all networks, which could leave your computer vulnerable.

To configure your firewall for each network location type, go to your firewall’s settings and look for the option to add or edit location types. Then, add a new location type for each network you connect to and configure the firewall rules for each one.

5. Use a whitelist approach

A whitelist approach means that only specific, known, and trusted applications are allowed to run on a system. All other applications are automatically blocked. This is in contrast to a blacklist approach, where known bad applications are blocked and all others are allowed.

The advantage of a whitelist approach is that it’s much more difficult for an attacker to find and exploit a weakness in an application that’s not on the list. Attackers often rely on automated tools that scan systems looking for vulnerabilities in common applications. If an application isn’t on the list, the attacker’s tool will simply move on to the next target.

A whitelist approach also makes it easier to keep track of which applications are installed on a system. This can be important when auditing systems or investigating incidents.

Of course, using a whitelist approach requires some upfront work to identify and configure the applications that should be allowed to run. But the extra effort is well worth it from a security perspective.

6. Make sure you have an up-to-date antivirus program installed

Your antivirus program is your first line of defense against malware. It works by scanning files for known patterns of viruses and other malicious code. If it finds a match, it will either quarantine or delete the file to prevent it from infecting your system.

However, in order for your antivirus program to be effective, it needs to have a up-to-date database of known virus signatures. Otherwise, it won’t be able to detect new strains of malware.

That’s why it’s important to make sure you always have the latest version of your antivirus program installed. Most programs will automatically update themselves, but it’s a good idea to check for updates manually on a regular basis, just to be safe.

7. Don’t forget about Windows Firewall

While it may not be as feature-rich as some of the other options on this list, Windows Firewall is still a very solid and reliable option. It’s also important to note that Windows Firewall is included with every single version of Windows, so there’s no need to go out and purchase any additional software.

If you’re looking for a host-based firewall solution, be sure to give Windows Firewall a closer look.

8. Update your operating system regularly

Operating system updates usually include security patches for vulnerabilities that have been discovered. By keeping your operating system up to date, you can help protect your computer from attackers who are trying to exploit known vulnerabilities.

Some attackers will try to take advantage of vulnerabilities that have already been patched, but they may not have success if you’ve installed the latest updates. That’s why it’s important to install updates as soon as they’re available.

If you’re using a Windows computer, you can set it to install updates automatically. For other operating systems, you’ll need to check for updates manually, but it’s still a good idea to do this on a regular basis.

9. Check that your firewall is working properly

A firewall is only as good as its configuration. If it’s not configured properly, it might not be blocking the traffic you think it is. Additionally, firewalls can sometimes develop problems that cause them to stop working correctly. For example, a software update might introduce a bug that causes the firewall to start blocking legitimate traffic.

To make sure your firewall is working properly, you should periodically check its logs to see if it’s blocking any traffic that it shouldn’t be. You can also use a tool like Nmap to scan your host from outside your network to see if the firewall is blocking any ports that it shouldn’t be.

10. Set up alerts and notifications

If your firewall is not properly configured, it can leave your systems and data vulnerable to attack. By setting up alerts and notifications, you can be alerted as soon as possible if there is a problem with your firewall configuration so that you can take corrective action.

Alerts and notifications can be sent via email, text message, or even push notification. Choose the method that works best for you and make sure to set up alerts for both critical and warning events.