Stateful Firewall vs. Stateless Firewall | Top 3 Differences

Stateful Firewall vs. Stateless Firewall | Top 3 Differences

A friend invited you to a party. At the main entrance, the doorman lets you in only if your name is on the list. That’s a stateless firewall. But when the doorman asks for your name, age, and invitation card, that’s a stateful firewall.

Stateful firewalls remember everything about your network connection. They only allow you to use the network if your information matches the “state table.” Stateless firewalls don’t remember you, and they authorize you to use the system as long as you provide the correct credentials.

Stateful firewalls vs. stateless firewalls. How do they work? How do they compare? That’ll be the main topic today.

What Is A Stateful Firewall?

A stateful firewall keeps detailed records of each active network connection by filtering the data packets.

It’s a type of firewall that monitors traffic sources end-to-end. Furthermore, stateful firewalls can detect traffic patterns and allow\block them as needed.

The stateful firewall can handle heavy traffic faster and more securely than stateless firewalls. It’s also better at detecting and responding to malicious attacks.

Stateful Firewall In Practice

Stateful firewalls examine packets based on a set of pre-defined rules. These rules determine which traffic to let in the network and which traffic to block.

Stateful firewalls remember the packet’s data, which allows users to use the network in several sessions. However, if the data changed, stateful firewalls will block the user from accessing the network.

Stateful Firewall In Action

A Transport Control Protocol (TCP) connection through the stateful firewall happens by recording the connection’s data. The stateful firewall records port number, destination, source, IP address, etc.

What Is A Stateless Firewall?

A stateless firewall also monitors the network traffic based on source and destination.

Stateless firewalls don’t understand traffic patterns and only block them when they conflict with recorded rules.

Stateless firewalls also go by the Access Control List (ACL) name. It’s because they don’t analyze traffic. They follow the filters and rules that the network administrator set.

Stateless Firewall In Practice

Stateless firewalls allow or block traffic packets based on their source and destination. They only watch the incoming and outgoing traffic with elementary information without interfering.

Stateless Firewall In Action

The File Transfer Protocol (FTP) is the best example of stateless firewalls. When you login into an FTP server, you can transfer files between server and client freely.

Whereas in a stateful firewall, you’ll need to enter login information with every action you take.

Stateful Firewall vs. Stateless Firewall

Stateful firewalls are fast learners. They monitor, detect, and encrypt end-to-end traffic streams without much interference from the network administrator.

They provide more filtering powers to understand everything about the network connection in session.

They’ll detect and block malicious attacks faster than stateless firewalls.

Stateless firewalls provide a lower level of security than stateful firewalls. They’re much easier to fool because they follow pre-established rules. They can’t differentiate between a genuine connection request and a hacker pretending to be a user.

They can’t adapt to network traffic unless the network administrator updates the rules.

Because stateless firewalls don’t have previous data (Like Dory from Nemo), they do minimal data packet checks. In effect, it’s relatively easier to gain unauthorized access to the network if you the hacker look genuine enough.

Pros And Cons Of Stateful Firewalls And Stateless Firewalls

Pros Of Stateful Firewalls

Robust detection of cyberattacks.

  • Builds on previous experience.
  • Uses fewer ports for communication.
  • Proxy security and filtration balance.
  • Strong memory.
  • Keeps detailed logs.

Cons Of Stateful Firewalls

Slow data transfer.

Hard to configure.

Consumes huge computing power to maintain stateful tables.

Pros Of Stateless Firewalls

  • Easy and quick configuration.
  • Fast performance.
  • Can handle heavy traffic.
  • Cost-effective.

Cons Of Stateless Firewalls

  • Easy to manipulate by hackers.
  • Minimum network monitoring.
  • Configuration needs for maximum security.
  • Vulnerability to SYN/ACK packets.

Stateful Firewalls vs. Stateless Firewalls: Which Is Better?

Stateful and stateless firewalls serve different purposes for different organizations.

Security isn’t something you should skimp on, so it’s vital to choose the best firewall for you.

It’s why you should ask these questions:

  • What is the day-to-day traffic flow intensity?
  • Which operating system do you use?
  • Which network hardware do you use?
  • How will the firewall work within your network?
  • What’s the size of your organization?
  • Aside from security reasons, why do you need to install a firewall?
  • Who will be using your network?

Most of all, you need to consider your budget for security.

Stateful Firewalls Are For Big Networks

Stateless firewalls will work best for a large organization that needs more network security. Stateful firewalls require sophisticated software, hardware, and setup to work effectively.

Large organizations are more open to attacks, and so they need advanced security measures.

With both in-house and remote employees accessing the network regularly, there’s a need to tighten security.

Plus, large organizations are more likely to have the resources to hire a network security specialist to configure stateful firewalls.

Stateless Firewalls Are For Small Networks

On the other hand, stateless firewalls are budget-friendly, easy to install, configure, and maintain.

A security-conscious small business owner can more readily have a stateless firewall in place.

Small businesses don’t or can’t afford an advanced level of security because the traffic they get isn’t heavy.

Besides, they need a highly-performing agile firewall to move fast.

A stateless firewall is more than enough to handle daily business routines while having a dedicated bodyguard.


Stateful and stateless firewalls work differently to achieve similar goals: securing your network.

So, sit with your team, and decide your security needs. A large organization may benefit from a stateless firewall when they’re in a low-threat level industry.

A small business will enjoy the security of a stateful firewall when they’re working in a highly regulated industry.

There’s no rule except that security is a cornerstone for digital success.

Remember, a firewall is something you don’t know you need until it’s too late. So, be ready and don’t rely on convenient solutions because you can get hit when you least expect it.

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