A firewall is a cybersecurity tool dedicated to securing the outer parameters of a network. They come in a variety of types depending on their location in the network, the amount of network traffic they’re capable of handling and their methodology of protection.
One type of firewall software that focuses on packet inspection is a stateful inspection firewall.
Continue reading to learn more about the functionality of a stateful inspection firewall solution, how it works, its pros and cons, as well as examples available on the market.
For more information, also see: Why Firewalls are Important for Network Security
How Do Stateful Inspection Firewalls Work?
A stateful inspection firewall uses network-based software to monitor the condition and states of active network connections. It inspects and analyzes the data packets exchanged during communications, scanning for data risks or unauthorized behavior.
Situated in the Open Systems Interconnection (OSI) layers 3 and 4, it’s active in both the network and the transport layers, where the majority of network activity occurs. Sometimes referred to as a dynamic packet filtering firewall, it can be configured for various levels of security and network access permissions.
By focusing on a network’s current state, the firewall software recognizes and monitors in-network devices as well as the types and targets of connection they’re looking to make.
While basic and traditional firewalls are only capable of blocking traffic previously identified as malicious or unauthorized for entering or leaving the network, stateful inspection firewalls take a more targeted approach. They monitor and analyze the context and condition of all incoming and outgoing network communications in order to determine whether they’re safe and permitted or not.
A stateful inspection firewall also inspects the data inside the exchanged packets, checking whether they contain anything that poses a threat to the network’s security or integrity. They can be made to work alongside tunneling and encryption algorithms to improve the state of security by preventing data interception.
For more information, also see: Artificial Intelligence in Cybersecurity
Top 6 Stateful Firewall Features
There are numerous features that are exclusive to stateful inspection firewall solutions, with other features that they share with traditional and other varieties of firewall software, such as:
1. Policy implementation and enforcement
Stateful firewalls can be used for setting and enforcing the security and privacy policy for the entirety of the network. Similarly, depending on the reach of the firewall, user behavior and access policy can also be centralized through the firewall software or hardware.
2. Intelligent defense
Compared to static firewall solutions, stateful inspection firewalls are capable of employing AI and machine learning-powered defense mechanisms. Traffic configurations can be simultaneously applied for both inbound and outbound network traffic, saving system admins time and energy.
3. Traffic filtering
Through smart and in-depth packet inspection and network traffic filtering, stateful firewalls can be set to protect against denial of service, malware, and brute force attacks.
4. Network monitoring
Operating on the third and fourth layers in the network, stateful firewalls monitor direct communications, and they can be integrated with application-monitoring and filtering solutions that mitigate the risk of backdoor attacks and data leaks.
5. Communication protocol management
In addition to packets and network traffic, stateful inspection firewalls also control the communications protocol the network’s users and devices are allowed to communicate with. Furthermore, it can collect information regarding the protocols in use, and control for security and privacy.
6. Efficient traffic processing
Stateful firewalls can be set to handle massive amounts of network traffic without sacrificing the quality and reliability of their security. They use a dedicated part of the network’s computational resources and memory storage to manage their logs and tracking of malicious attempts on the network to achieve future detection and analysis.
What are the Advantages of Stateful Inspection Firewalls?
Opting for a stateful inspection firewall solution offers many benefits and advantages to your network’s security and privacy goals, such as:
- Minimizing the number of communications ports.
- Built-in network activity tracking and logging.
- Blocking network infiltration attempts through data monitoring.
- Centralizing network security management.
- Logging attacks for cyber forensics and in-software learning.
- Configurations to deter specific cyber attacks.
- Unified Threat Management (UTM) capabilities.
Packet data analysis is a highly sophisticated task that network operation centers use to identify security threats and abnormal behavior.
What are the Disadvantages of Stateful Inspection Firewalls?
If you’re looking to implement a stateful inspection firewall software solution as your only or primary network security solution, it’s important to understand where the technology falls short and may need to be paired with separate tools. These disadvantages include:
- Inability to monitor or properly control traffic on the seventh or application layer in the network.
- Can be rendered obsolete without frequent software updates.
- More susceptible to Man-in-the-Middle (MITM) attacks.
- Complex setup and configuration.
- Lack of support for all types of communications protocols.
- No support for user-based authentication of network connections and traffic.
- Being connection-based, they’re unable to monitor and interfere with network activity outside of established communications channels.
Examples of Stateful Inspection Firewalls
Stateful inspection firewalls are part of the global deep packet inspection and processing market, which had an estimated value of $16.41 billion in 2020. It’s projected to maintain a compound annual growth rate of 22.14% over the analysis period from 2021 to 2028, reaching an estimated $80.68 billion.
The market is dominated by a number of cybersecurity and cloud service providers that offer their own stateful firewall solutions.
Some of the leading vendors on the market include:
Barracuda Networks
Barracuda Networks is a Campbell, California-based provider of cybersecurity, storage, and computer networking solutions and products. In the security realm, Barracuda offers a variety of solutions ranging from email and web surfing security to network-based and direct web hacking protection.
Barracuda’s CloudGen firewall solution is built with several security solutions and features with stateful deep packet inspection at the heart. Not only does it scan and monitor the identifiable data on the outside of packets, but it also delves into the header and contents of your network’s traffic.
Cisco Systems
Cisco Systems is a San Jose, California-based digital communications and networking company. It helps organizations and enterprises build, manage and secure their computer networks and devices through automation and data collection and analysis.
The Cisco ASA (Adaptive Security Appliance) is a firewall hardware that merges the security capabilities of a firewall, an antivirus and a VPN. While the ASA can be configured to operate as a stateless firewall, its primary condition is stateful, enabling it to defend your network against attacks before they occur.
Juniper Networks
Juniper Networks is a Sunnyvale, California-based networking and technology company that designs, develops and sells solutions that facilitate high-performance networking for enterprises and organizations. Its offerings range from network hardware and management software to network security and software-defined networking technology.
The SRX Series by Juniper is a family of high-performance service gateways that combine security, networking, and traffic routing capabilities. It’s a stateful solution that creates sessions by receiving TCP SYN packets, where the traffic matches the current communication session.
Bottom line: Stateful Inspection Firewalls
A stateful inspection firewall is a type of firewall that operates primarily on your network’s third and fourth layers. It employs in-depth packet inspection to detect and intercept threats before they can gain access to the network’s resources.
It can’t reach the application layers on its own, which leaves a gap that can be filled with a number of external security tools. The global market for stateful firewalls and packet inspection security technologies is rapidly growing, with many trustworthy cybersecurity and networking companies offering their stateful firewall solution for consumers.
