The 6 Tradeoffs Between a Stateful vs Stateless Firewall


Disclosure: Our content is reader-supported, which means we earn commissions from links on Digital. Commissions do not affect our editorial evaluations or opinions.

As more of our data goes on the cloud and more of our time gets spent online, the need to secure our most precious digital assets can’t be overstated. 

This is why firewalls and other security tools are so important—because they protect our home and business networks from hackers and other threats. 

A firewall is essentially a barrier or checkpoint on your network that watches your computer’s internet connection to guard your information. Its primary function is to allow or deny traffic based on a set of predefined rules.

However, not all firewalls are built alike. Of the three types of firewalls, an organization will usually choose to deploy a stateless or a stateful firewall. 

A stateful firewall, as the name suggests, is one that keeps track of the state of network connections. It does this by examining the data packets within the network to determine where they’re coming from, where they’re going, and what kind of traffic is being relayed.

In comparison, a stateless firewall does not track the state of network connections. Instead, it examines each packet individually, making its decisions based on the information contained within each packet.

Because of these radical differences, these two types of firewalls come with very different strengths, weaknesses, and unique benefits. As a result, neither one is necessarily “better” than the other—it all comes down to the individual needs of your network and your business. 

6 Tradeoffs Between a Stateful vs. Stateless Firewall

The main goal of network security is to protect your organization’s data from nefarious cyberattacks by using whatever devices, software, and protocol that can help. 

Naturally, the first line of defense is the firewall, which can identify and prevent unauthorized access—as long as you choose the right one.

Altogether, there are six key comparisons worth considering when making a decision between stateful and stateless firewalls. 

1. Stateful firewalls consume more resources

The first tradeoff to consider is the volume of resources consumed.

Stateful firewalls, which can operate at the network layer (layer 3) or the transport layer (layer 4), work by inspecting packets and the context of network connections. Due to how stateful firewalls keep track of connection states, they need to be able to handle more packets with greater scrutiny. 

This almost inevitably leads to a significant consumption rate and a drain on resources—especially when background processing comes into play. Consequently, it can really slow down your network.

Meanwhile, stateless firewalls are a much faster alternative because they operate by examining the source and destination addresses of individual packets. This means they ignore the connection states and can therefore resolve incoming packets much faster. 

Stateless firewalls can also help you skirt the problem of hogging resources by offering faster speeds and greater overall efficiency when handling minor tasks. In other words, they aren’t as burdened by complex connection-state handling as stateful firewalls. 

Altogether, stateless firewalls are far more suitable in high-traffic, low-risk situations. With their superior speed, they can assess packets quickly without putting a strain on network resources. Meanwhile, when the security level requires a bit more intensive work, stateful firewalls are usually worth the performance hit.

2. Stateful firewalls are less likely to trigger false positive alarms

Stateless firewalls can have a tendency to put your network in a constant “fight or flight” type of condition. This isn’t as common with stateful firewalls, and that’s simply due to the way they track the state of connections. 

Stateful firewalls can and will recognize established connections, so they’re more sensitive about blocking traffic rather than tossing up a red flag whenever anything that might be suspicious comes their way (as stateless firewalls tend to do).

For instance, let’s say you’ve configured your stateless firewall to block any incoming traffic on port 80, which is typically used for HTTP traffic. If a user tries to access a legitimate website that uses HTTP, then a stateless firewall might falsely identify this traffic as malicious and block it. This would be a false positive. 

Overall, stateless firewalls are way more likely to generate false positives and block legitimate traffic because they lack context. 

In practical terms, this means that stateful firewalls tend to offer more nuanced control over your traffic—which can be super useful for networks that are more complex or transmit more sensitive data. 

Financial institutions and healthcare providers, for example, may find this particularly advantageous because they generally have stringent security requirements. With stateful firewalls, they can make sure their networks remain secure.

3. Stateless firewalls can apply more flexible rules 

Let’s say you’re an IT administrator who’s in charge of securing your organization’s network. If your rules are highly structured and follow strict guidelines, a stateful firewall will enable you to enforce those rules with a bit more precision. In other words, you’ll have more reliable, consistent protection.

However, if your traffic is more varied—and therefore more unpredictable—a stateless firewall can be a better choice because it lets you apply rules right at the packet level. This can be especially helpful when you need to let certain traffic pass through that might not fit into a predefined set of rules so easily.

For example, if a software development company frequently collaborates with third-party vendors, it’s very likely that the traffic coming in from these vendors is highly varied. By using a stateless firewall that can apply more flexible rules, the company would be able to manage its varying traffic patterns without compromising its security. 

4. Stateless firewalls don’t need to maintain information about each connection

Another chief benefit of stateless firewalls is that they don’t need to maintain information about each and every connection—because they don’t track sessions or connection states in the first place. 

Instead, they focus on filtering traffic based on predetermined policies and rules. This means they can be exceptionally adept at handling massive volumes of network traffic, as they just don’t demand the same processing power, memory, and/or resources as stateful firewalls.

One instance where this can be especially useful is in a cloud computing environment with virtual servers and workloads that frequently increase and decrease. In this environment, a stateless firewall could theoretically be deployed to make sure the traffic going in and out of the cloud-based resources follows a predetermined set of rules. 

Furthermore, since a stateless firewall doesn’t require the same investment or overhead as a stateful counterpart, it could be a great choice in a dynamic, cloud-based environment. 

5. Stateless firewalls offer less control

Although stateless firewalls can be more agile and light-footed, they offer far less precision. 

Without storing the state of a network connection, stateless firewalls treat each packet that passes through them as individual entities—with no consideration for the packets that came before or after them. As a result, stateless firewalls are pretty limited in their ability to differentiate between permitted and unpermitted traffic, leaving them more vulnerable to a few types of attacks.

With a stateful firewall, however, when an initial request to access a secure website is allowed to pass through, subsequent packets are then identified as part of the same connection. This gives users a lot more freedom to retrieve data without compromising security, ultimately giving them more control, less frustration, and increased productivity. 

6. Stateful firewalls have a higher price tag

Stateful firewalls are generally considered to be more advanced, functional, and efficacious than stateless firewalls. At the end of the day, they’re better at tracking the state of different network connections and then making decisions on that state—which is kind of the whole point of a firewall in the first place. 

That said, with that thoroughness comes a heftier price tag. Likewise, stateful firewalls also require more powerful hardware to operate at full capacity, and they are more complex to set up and configure. Once operational, stateful firewalls will require ongoing maintenance and updates to make sure they stay at peak performance.

Key Takeaways

Choosing between a stateful and stateless firewall is a matter of balancing their tradeoffs. 

While stateful firewalls will undoubtedly provide more advanced security functions, they also require more memory, processing power, and dolla dolla bills to operate. 

Of course, this doesn’t mean that stateless firewalls are a bad choice, because they can even be the better choice for certain businesses with less complex network architectures. 

When it comes to making the decision for your business, be sure to weigh the pros and cons based on how they would affect your company so you can choose the right firewall to protect your network.

Scroll to Top