Stateful vs Stateless Firewalls: Differences Explained

Posted on Nov 13, 2023 by

A firewall is an application that monitors and regulates network traffic. It operates according to pre-written security rules. Stateful and stateless firewalls can also monitor data behavior and identify patterns in behavior. Compared to stateful firewalls vs stateless firewalls, understanding the distinctions between their technologies will assist in guaranteeing that your company is adequately protected.

What is a Stateful Firewall?

A stateful firewall can track the status of network connections. It monitors the status of network connections and determines whether to permit traffic depending on the connection's historical state. To swiftly detect and stop malicious traffic, stateful firewalls generate a state table to log network connection statuses. Stateful firewalls can offer stronger security and more flexible traffic control. A stateful firewall verifies each data packet's communication channels, content, and data properties. When any irregularities are discovered, a stateful firewall can filter out suspect data by monitoring the behavior of data packets. For businesses with strict cyber security needs, this is crucial.

Stateful vs Stateless Firewall: What is the difference?

What is a Stateless Firewall?

A stateless firewall is a filter-based firewall that only checks the header information of each data packet and does not track the connection status. A stateless firewall filters or blocks network data packets based on static values, such as addresses, ports, protocols, etc. Stateless firewalls do not create a state table, so the processing efficiency is higher than stateful firewalls. Still, they can not recognize and intercept some advanced attacks, such as DoS attacks. A stateless firewall can provide basic security and Byte Flow Control, but it is not as flexible as a stateful firewall, so it is more suitable for simple scenarios.

Pros and Cons: Stateful Firewall vs Stateless Firewall

Stateful firewalls and stateless firewalls each have their advantages and disadvantages. Here are some details below.

Pros of Stateful Firewalls

  • Stateful firewalls are highly effective at identifying fraudulent messages or unsolicited efforts.

  • Strong memory keeps important network connection characteristics.

  • They simply require a small number of ports to be open to function properly.

  • Robust attack prevention and thorough logging are features of stateful firewalls.

  • Stateful firewalls are intelligent systems that use the total of their historical and current data to inform their future filtering choices.

Cons of Stateful Firewalls

  • Viewing a webpage can be used to deceive some stateful firewalls into allowing or even attracting external connections.

  • Attacks by a man in the middle could expose more weaknesses.

Pros of Stateless Firewalls

  • Stateless firewalls deliver fast performance.

  • Stateless firewalls have historically been more affordable to buy.

  • Heavy traffic is no match for stateless firewalls, which perform well under pressure without getting caught up in the details.

Cons of Stateless Firewalls

  • Stateless firewalls do not inspect traffic

  • These firewalls require some configuration to arrive at a suitable level of protection.

  • The stateless firewall also does not examine an entire packet, but instead decides whether the packet satisfies existing security rules.

Difference:Stateful Firewall vs Stateless Firewall

The main difference between stateful and stateless firewalls is the way they handle data packets and the processing efficiency.

  • A stateless firewall doesn't maintain any remembered context (or "state") concerning the packets it is processing. Instead, it treats each packet as an attempt to travel through it in isolation without considering packets that have been processed previously.

  • A stateful firewall is a packet filter that dynamically updates rules. If the data packet is a new connection, it is checked according to security policies. If the data packet is part of an existing connection, it is matched to the state table and update table.

  • Stateful firewalls can provide better security and more flexible Byte Flow Control, but the processing efficiency is relatively low; a stateless firewall has high processing efficiency, but the security and Byte Flow Control capabilities are relatively weak. In practical applications, it is necessary to choose the appropriate firewall type according to the actual situation.

Stateful vs Stateless Firewall: What is the difference?

How to Choose Firewalls for Your Business?

When deciding which firewall to choose, consider the following factors:

  • Usage scenarios: If used in scenarios with high-security requirements, it is best to choose a stateful firewall. If used in simple scenarios with low-security requirements, a stateless firewall is also a suitable choice.

  • Available resources: Can you afford to separate the firewall from the internal network by placing it on separate hardware or even the cloud? The traffic load that the firewall needs to filter and whether the traffic load remains consistent also plays an important role.

  • Required level of protection: The number and type of firewall should reflect the security measures required for the internal network. Enterprises handling sensitive client information should ensure that data is protected from hackers by enhancing firewall protection.


Investing in a good firewall is a critical first step in safeguarding your company's assets, personnel, and data. Your company can safeguard its network assets by selecting stateful firewall vs stateless firewall with awareness. Choose the firewall type that will offer your company the most protection and support by looking through a large range of firewalls.

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