Stateful vs. Stateless Firewall: Comparison & Key Differences

The cases of stealing of digital files have been on the increase these days, demanding strong business network protection.

Protecting customers from digital threats should be the topmost priority of managed service providers. For this reason, they need to get the best defense from malicious activities online.

Computer firewalls protect the network against threats.

They offer an impressive solution to the cybersecurity needs of businesses. Well, not all of them are the same.

The firewall can be categorized into a stateful vs. stateless firewall, depending upon its strengths and weaknesses.

Check out this post to know the difference and the advantages and disadvantages of stateful and stateless firewalls.

Stateful vs. Stateless Firewall

Let us have a look at each of them to know the difference between the two.

Stateful Firewall Definition

This firewall monitors the state of the network connections that are active.

It analyzes the data packets of the connection that seek entry to the network and not of those data packets that are in isolation.

This type of firewall is mostly used in modern networks. It offers better usability and comes with easier configurations.

How Stateful Firewall Works?

The stateful firewall inspects a packet, and if it matches an existing rule in the firewall, then that packet is allowed to pass. Next, there is an addition of an entry in the state table. This packet that has been approved by the firewall can now travel freely in the network.

In contrast, the traffic and the data packets that don’t meet the above-discussed requirements aren’t allowed to pass through and are thus blocked.

Stateful Firewall Example

TCP is an example of this. Transport Control Protocol (TCP) saves the record of its connection by saving its port number, IP addresses, and source and destination addresses.

The connection in TCP is made with a three-way handshake and is ended with a two-way exchange.

Stateful Firewall vs. Packet Filter

The packet filter monitors only individual packets. On the other hand, the stateful firewall examines the complete traffic on a given connection.

It makes use of the source and destination IP address, and the ports. It keeps the connection states track in a table.

Stateless Firewall Definition

The stateless firewall holds the responsibility of watching the network traffic. They have no data on the traffic patterns and restrict the pattern based on the source and destination address. The stateless firewall is also termed as the Access control list (ACL). It doesn’t inspect the complete traffic.

In simple words, the stateless firewall does not remember the state and keeps on filtering the packet according to the rule list that passes through it.

It makes decisions without any further context.

Also Checkout Rule Based Access Control Model Best Practices

How Stateless Firewall Works?

Here independent packet evaluation is done. The stateless firewalls monitor the incoming traffic packets. They allow or deny the packet’s entry into the network based on their source and destination address or some other information, for example, the traffic type.

In simple words, these firewalls view some basic information of the data packets and then allow or block them according to it.

Difference Between Stateless and Stateful Firewall

A stateful firewall monitors the network connection state continuously. It keeps an active eye on the packets entering the network. This firewall checks not only the packet context but also the headers to validate them. The traffic that this firewall approves can move freely in the network.

On the other hand, the stateless firewall makes use of some static information for network protection. This static information can be source and destination address or some other information. This firewall approves or disapproves of the packet entry into the network based on some pre-provided information.

Recommended Read Types of Authentication Methods

Advantages and Disadvantages of Stateful and Stateless Firewall

Stateful Firewall Pros and Cons

Pros

• They deficient the network based on the pattern of the traffic
• This firewall offers a brilliant balance between the packet filter performance and the application proxy security.

Cons

• Here the data transfer rate is a bit low.
• In stateful firewall tables have to be maintained and to parse the access list, logic is used. All this demands a higher memory and processor power.

Stateless Firewall Pros and Cons

Pros

• Less complex
• Simple to implement
• Highest performance firewall

Cons

• This firewall assumes that the packet information can be trusted.
• If an attacker sends SYN/ACK as an initial packet into the network, then the host will ignore it, and this way, the packet will pass the firewall easily.

Stateless Firewall Attack

This firewall cannot prevent attacks to the fullest.

IP buffer flow was an attack that occurred in the 1900s.

In such an attack, the attacker takes the benefit of the structure of the IP datagram and sends IP datagram fragments having illegal offsets.

Final Words

The stateless firewall is the oldest firewall that offers security by packet filtering of the incoming traffic.

It uses some static information to allow the packets to enter into the network.

This firewall inspects the packet in isolation and cannot view them as wider traffic. Due to this reason, they are susceptible to attacks too.

On the other hand, the stateful firewall is an advanced firewall that tracks the active connection and the network state. This firewall has the ability to check the incoming traffic context.

By knowing the stateful vs. stateless firewall difference, you can protect your network in a better way.

Also, Checkout IDS vs. IPS: What’s the Difference?