5 reasons to use a stateless firewall (+3 main disadvantages)

In networking, “state” refers to the context or session data of an existing network connection. Therefore, a stateful firewall keeps track of the state of each connection passing through it, whereas a stateless firewall does not.

Although they may seem less restrictive, stateless firewalls are incredibly useful for securing home and business networks. They use ACLs (Access Control Lists) to determine what traffic to allow and what traffic to block.

Of course, not tracking the state of network connections means that a stateless firewall can’t tell you as much about the traffic on your network as a stateful firewall. The benefits of a stateless firewall come with tradeoffs.

Businesses often balance these trade-offs by using both types together, with stateless firewalls handling bulk traffic filtering at the perimeter and stateful firewalls offering deeper inspection behind them.

By the end of this post, you’ll know when stateless firewalls work really well, and when another solution might work much better.

Five reasons to use a stateless firewall

1. They are efficient

The biggest advantage of using a stateless firewall is efficiency. Since they only examine individual packets (instead of tracking connection state like their heavily stateful counterparts), stateless firewalls are like weak, mean, security machines.

This makes them far more useful when handling high amounts of traffic. For example, since they don’t have to take into account the specific details of each connection that passes through, stateless firewalls won’t eat up as much memory and processing power.

For example, if you’re running a large-scale website that gets a lot of traffic, you won’t want your firewall to slow things down. With a stateless firewall, you can establish strong network security protections without jeopardizing a website’s performance.

See: Avoid these mistakes when configuring network security.

2. Stateless Firewall is easy to install and maintain

Stateless firewalls are easier to set up than stateful firewalls.

Stateful firewalls dynamically maintain state tables to track ongoing connections, ensuring that traffic flow is legitimate by monitoring session information.

In contrast, stateless firewalls rely on a fixed set of filtering rules, such as allowing or blocking packets based on IP address, port, or protocol. This makes stateless firewalls easier to configure and less resource-intensive, although it also makes them less well suited for dynamic or context-dependent traffic than stateful firewalls.

3. Stateless Excel at the Network Perimeter

Stateless firewalls are often used as the first line of defense in network security due to their simplicity and effectiveness in blocking unwanted traffic.

They are particularly useful in scenarios where only basic access control is needed, such as filtering traffic between trusted and untrusted networks. It protects specific services from common attacks such as port scans, denial-of-service (DoS) attacks, or VoIP fraud.

While they cannot offer the deep inspection or session awareness of a stateful firewall, they can serve as an effective initial barrier, blocking simple, high-volume threats before they reach more sensitive parts of the network. Can reduce the load on more advanced systems.

4. They are naturally less insecure

Stateless firewalls do not keep track of past traffic or active connections, making them less vulnerable to certain types of attacks targeting the firewall’s memory or stored data.

Instead, stateless firewalls compare incoming packets against their pre-defined “allow” and “deny” rules, ensuring that traffic is only allowed into the network if it meets specific criteria. This straightforward approach ensures that only authorized traffic enters the network.

Since they do not need to manage the details of each connection, stateless firewalls avoid some of the vulnerabilities that can arise when a firewall tries to remember everything, such as becoming overloaded during the process. Different types of DDoS attacksWhere attackers flood the system with too many requests.

Stateful firewalls provide deeper inspection and more granular security, but it introduces additional complexity that can be exploited by attackers. Stateless firewalls, with their simple design, avoid this risk entirely.

5. Stateless Firewalls are cost-effective and affordable

Because they do not require the advanced features of stateful firewalls, such as session tracking or deep packet inspection, their hardware and maintenance costs are significantly lower. This makes them an accessible option for organizations with limited IT budgets or small networks.

Stateful firewalls are more expensive because of their advanced features, such as integrated Intrusion Detection and Prevention SystemThese firewalls also require more processing power, memory, and specialized hardware to manage real-time traffic analysis and maintain security.

Main disadvantages of stateless firewall

While stateless firewalls have their advantages, they also come with some disadvantages.

1. Minimal packet inspection capabilities

Since it does not keep track of connections, a stateless firewall will not maintain a table of all past connections that have passed through the firewall. This makes it faster and easier to handle large amounts of traffic, but it comes with minimal packet inspection capabilities.

For example, stateless firewalls can only inspect individual packets based on headers and protocol, meaning they cannot see the contents of the packets themselves. This makes them less effective at detecting and preventing more sophisticated attacks that can bypass simple packet inspection, such as attacks that use encrypted traffic.

Furthermore, due to the lack of connection tracking, a stateless firewall cannot always distinguish between legitimate and malicious traffic. This may result in unnecessary interruptions to legitimate traffic, which may disrupt business operations. This makes it even more difficult to modify the firewall, because stateless firewalls cannot recognize connection states – so they cannot dynamically allow or deny traffic based on them. learn more about How does stateful inspection work?,

2. Difficult to measure

The biggest downside to stateless firewalls is that extending them can be an absolute nightmare in some scenarios.

The problem lies in the fact that a stateless firewall only examines individual packets to determine whether to allow or deny them. This means that, as the number of connections to your network increases, so does the number of rules in your firewall. Therefore, when there is a huge amount of traffic on your network, it can be extremely difficult to manage and maintain.

Unfortunately, with stateless firewalls, you need to create manual rules for each type of packet traveling through the network. This can lead to a situation where there are too many rules to manage – leading to network performance issues, security flaws, and massive administrative overheads. learn more about How to create a firewall policy Whatever works for your network.

3. Initial configuration to work properly

Although a stateless firewall is easier to set up than a stateless firewall, the process is not at all easy.

Stateless firewalls may require considerable initial configuration to function properly. For example, since they do not maintain connection state, they must rely on other factors – such as IP addresses and port numbers – to determine whether incoming packets are allowed into the network.

This means that, in addition to the above filtering rules, some additional settings require careful configuration to ensure that legitimate traffic is allowed while malicious traffic is blocked. learn more about How to set up a firewall properly,