What Are the Differences Between Each Firewall Type?

Firewall types differ in how they keep threats out of your network. They can be hardware or software, cloud-based or on-premises.

A proxy firewall inspects the context and content of data packets to determine whether they should pass through your network. This type of firewall can slow down network speeds but offers granular security control.

Packet Filtering Firewall

Firewalls control access to your company’s systems by analyzing each data packet in and out of the network. They then compare it to preconfigured rules to determine whether or not to pass the data through. If the data packet violates a law, the firewall will block it.

Packet filtering firewalls are based on access control lists (ACLs) that examine upper-layer protocol ID, source and destination ports and addresses, ICMP types and codes, flags, and the physical interface it’s passing through. These ACLs determine the allowed and blocked information based on the set policies. For example, a company may allow file transfer protocol (FTP) traffic from one specific internal IP address to another while blocking all other FTP traffic.

Since it only needs one screening router to function, this firewall is frequently the least expensive and easiest to use. The speed at which it operates allows or rejects each packet in milliseconds depending on the source and destination ports and addresses. These firewalls also don’t need users’ cooperation or client machine software installation, and they are incredibly transparent to users.

These are the differences between each firewall type. However, this kind of firewall could be more secure than alternative solutions like stateful inspection or proxy firewalls. Therefore, if hackers know how to accomplish it, they can take advantage of the rules and break into your system.

Proxy Firewall

A proxy firewall, also called an application firewall or gateway firewall, filters messages at the application layer. It enforces network policies through a server as an intermediary between client systems. Firewall proxies can cache web traffic to reduce bandwidth demands, compress data and filter traffic to identify viruses or malicious code.

Firewall proxy servers also hide internal network architecture from the outside world. It is accomplished by requiring all direct connections between end systems to go through the firewall proxy, thereby eliminating private IP addresses from escaping the protected system.

This connection control method is more efficient than packet filtering because it doesn’t require memory capacity for inspecting each data packet. It also allows for better monitoring of application payloads and offers the highest level of security against the most advanced threats.

The downside is that a proxy firewall provides less control and granularity than a stateful inspection firewall because the security rules are enforced through a single point of contact with the firewall server. It can make it challenging to keep up with new applications and changes in existing ones and slow down performance. Also, it may be easy for ambitious users to bypass the firewall by modifying the configuration of a proxy server or PAC file.

Stateful Inspection Firewall

The stateful inspection firewall tracks connections and uses this information to assess incoming data packets. It offers more granular control over the threats the firewall detects and blocks. A stateful inspection firewall typically collects all the information from a connection, including attributes like source and destination IP addresses, ports, and sequence numbers. This information creates a profile of “safe” bonds. When a new data packet tries to connect, the firewall compares it to this profile and decides whether it should proceed.

It is useful for protocols that use handshakes to establish a network connection, such as TCP. Firewalls that can remember the state of these connections can recognize probe packets that look like part of a handshake and block them because the firewall knows this isn’t good, ongoing communication. Firewalls that use a stateful inspection function can also track the state of existing communication sessions and record how these communication sessions were established.

Many cybersecurity vendors offer stateful inspection firewalls as standalone products or integrated with other services. For instance, checkpoint’s firewalls integrate with its app-ID engine to perform deep packet inspection that goes beyond the actual content of a data packet and checks for malicious code in the application layer.

Next-Generation Firewall

The term’ next-generation firewall’ refers to a security device that combines traditional filtering functions with advanced technologies, such as deep packet inspection and intrusion prevention systems. These features are designed to prevent more sophisticated malware attacks and external threats. NGFWs are often part of a UTM (unified threat management) plan that includes antivirus software, a content filter, and a network security architecture design service.

A next-generation firewall can identify and block data packets that violate specific policies. It is because they analyze the network traffic data layer, inspecting each pack’s contents to identify possible threats. This type of firewall typically requires more computing resources and may result in a slower transfer rate for data packets than other types of firewalls.

Many reliable NGFWs are on the market, including Fortinet FortiGate. It features a variety of security capabilities, including deep packet inspection and SSL decryption. CheckPoint’s NGFW is another popular option because it offers high-performance appliances, SASE and ZTNA integrations, and a self-updating platform. Palo Alto’s PA Series is another top choice, as it safeguards cloud-native apps and can be deployed as a single entry point to front-distributed applications.