Types of Firewalls for Cybersecurity

Key takeaways

A firewall helps create a protective barrier between trusted internal networks and untrusted external networks, like the internet. 

• By restricting and monitoring the flow of data packets, firewalls safeguard networks against unauthorized access and malicious attacks, among other potential threats.

• Widely deployed firewalls include packet filtering firewalls, application-level gateways, next-generation firewalls, and unified threat management firewalls.

• You can regularly update your firewall software and hardware to protect against known vulnerabilities.

Discover the unique features and benefits of different types of firewalls, and learn how to choose the best firewall for your network security needs. Afterward, if you’re ready to advance your cybersecurity skills, enroll in New York University’s Introduction to Cyber Security Specialization to gain insights into modern information and system protection technology and methods.

What is a firewall?

A firewall is a security system that monitors incoming and outgoing network traffic, creating a protective barrier between trusted internal networks and untrusted external networks, like the internet. 

Firewalls are key components of many cybersecurity strategies. They use a set of predefined rules to determine whether to allow or block the flow of certain data packets, which are small units of information, to your network. By restricting and monitoring the flow of data packets, firewalls can protect your network from unauthorized access, malicious attacks, and other possible threats to your network’s integrity in order to safeguard your information.

Things to consider when selecting a firewall

When choosing a firewall, consider your network size, complexity, and the types of threats you might face. Additionally, think about the resources available for managing and maintaining the firewall, as well as the potential impact on network performance. By carefully evaluating these factors, you can make an informed decision about which firewall type is the best fit for your needs.

What are the 2 main types of firewall? Software vs. hardware

Software firewalls work on individual devices like computers or servers, protecting them from network-based threats. These firewalls are customizable and easy to update, but they can also consume system resources, potentially impacting performance. 

Hardware firewalls are standalone devices placed between your network and its connection to the internet. They provide a higher level of security, but they can be more expensive and harder to maintain than software firewalls.

Different types of firewalls in network security

Choosing the right firewall can make a huge difference in the security of your website or business. If your firewall is not the right size or does not have the right security features, you may experience lower performance or vulnerability to attacks. When choosing a firewall, consider key options such as the following:

1. Packet filtering firewalls

These firewalls examine data packets and either allow or block them based on source and destination internet protocol (IP) addresses, ports, and protocols. They're relatively simple and fast but might not offer the same level of protection as more advanced firewalls.

2. Circuit-level gateways

Circuit-level gateways monitor connections between networks, ensuring they follow proper protocols. These firewalls provide better security than packet-filtering firewalls but are still limited in their ability to inspect data payloads.

3. Stateful inspection firewalls

Stateful inspection firewalls monitor the state of active connections and use this information to determine if they should block or allow packets. They offer more in-depth security than packet filtering and circuit-level firewalls, as they can examine the entire data packet, including the payload.

4. Application-level gateways

Also known as proxy firewalls, application-level gateways act as intermediaries between clients and servers. They inspect data packets at the application layer, ensuring they adhere to specific protocols and are free of malicious content. This type of firewall provides strong security but can be resource-intensive.

5. Next-generation firewalls (NGFWs)

Next-generation firewalls (NGFWs) combine traditional firewall functions with advanced features like deep packet inspection, intrusion prevention system (IPS), and application awareness. They offer comprehensive security but might require more resources and management compared to simpler firewalls. NGFWs are often suited to large organizations that need to protect large volumes of data transfer.

6. Network address translation (NAT) firewalls

Network address translation (NAT) firewalls are a security feature that protects your private network by translating private IP addresses into a single public IP address. NAT firewalls act as gatekeepers, allowing devices to communicate with the internet while hiding their individual addresses, making it harder for outsiders to target them.

7. Cloud firewalls

Cloud firewalls reside in the cloud, and they provide security for cloud-based networks and applications. They offer the advantage of scalability and ease of management, as they can be easily deployed and updated. Cloud firewalls are particularly useful if you rely on cloud services or have a hybrid infrastructure, as they can provide consistent security policies across all environments.

8. Unified threat management (UTM) firewalls 

Unified threat management (UTM) firewalls combine multiple security features like antivirus, intrusion prevention, and content filtering into a single device. UTMs combine NGFWs with antivirus software, virtual private network (VPN) features, and intrusion detection to provide a comprehensive protection system. UTMs are useful for small and medium-sized businesses that need a wide range of security features without separate devices and management systems.

Which type of firewall is most effective?

Because UTM firewalls merge several layers of security into one unit, security organizations tend to believe this type of firewall is the most secure. UTM offers IT administrators the ability to control various security functions from one device rather than multiple, which allows for less complexity, better efficiency, and quicker threat detection and response.

Firewall best practices to follow

To ensure top performance and security, it's essential to follow best practices when implementing and managing firewalls. These practices include the following:

• Regularly update your firewall rules and configurations to stay current with emerging threats and changing network requirements.

• Implement a strong, consistent security policy across all devices and networks.

• Monitor and analyze network traffic to detect anomalies and potential security breaches.

• Update your firewall software and hardware to protect against known vulnerabilities.

• Segment your networks to limit the potential impact of security breaches and improve overall network performance.

Read more: Data Security Breach: What They Are, How They Happen, and More

Check out our free resources for cybersecurity professionals

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