What is a network firewall?

In simple terms, a network firewall can be defined as a gatekeeper that determines who or what data is allowed to enter a computer system.

A network firewall is a mechanism that applies to both individuals and organisations. It assists in scanning the incoming data from the internet to check if it contains a virus or is harmful to the device or existing data on the system.

Categories of network firewalls

There are two diverse categories in which the network firewalls can be classified based on how it is applied and in the system to which it is applicable. They are:

• Hardware firewalls: This network firewall form can be described as a mechanical component that provides firewall protection. It is usually attached to the internet modem or network hardware. It protects widespread network systems from large-scale hacking attempts.
• Software firewalls: This is the form of firewall installed directly onto a computer system through a program or application. This firewall protects computer data from low-level attempts at bypassing the protocols.

Benefits of using a network firewall

There are numerous benefits to using a network firewall. Some of which are:

• Protect the network from external activities: A network firewall protects a computer or several systems from outside agents which may attempt to extract data illegally. This can also prevent individuals outside the network at home or a workplace from gaining access to an internet connection’s login credentials.
• Shield data from internet viruses: Data is constantly stolen through various means, one of which is by using malware software that can render a computer making it inoperable. Once this is achieved, the information that the system contains is stolen. Installing a firewall helps identify the malware before the program is downloaded onto the computer system. This, in turn, protects sensitive information from falling into the wrong hands.
• Manage the network’s processing ability: Firewalls help networks remain available. This means that they can establish and maintain connections with other networks making it possible to process the incoming information quickly. This also blocks unwanted data and allows the network to process the information more easily.
• Maintaining the network's storage capacity: A firewall generally helps the computer network to maintain a connection with the cloud storage, a remote data service the company owns outside. Firewalls prevent individuals outside from gaining access to the cloud storage data.

Types of network firewalls

These are a few types of network firewalls commonly used:

• Packet-filtering firewalls

This firewall tracks data from packets and determines whether they follow an ACL (Access Control List), a network security engineer incorporated. This assists in improving the way the IP address of a system is verified and checks if the packet is safe to encounter. This kind of firewall is simple to set up and both for cybersecurity professionals and individuals eager to learn how the installation and configuration can be done successfully.

• Proxy server firewall

Proxy server firewalls are hardware systems intermediaries between a website packet and the computer system. This firewall creates a separate communication line to receive the information packet, preventing two networks from directly connecting. The received information through the network is accepted as packet materials. The security engineer connects the proxy server firewall to one computer system and then allows other systems to use its IP address to access the internet. This firewall reduces a network’s processing speed but often provides ample security for multiple people simultaneously.

• Application-layer firewall

This is a software program that monitors communication from outside networks. It scans all incoming material for harmful data or viruses to ensure that the other programs in the computer system do not fail. Some software automatically removes this form of harmful data, while others highlight potential issues for an individual to review manually. After installing this firewall program, the security engineer frequently updates its policies and protocols to fortify its protection capability. This firewall is often used to manage data between a network and website-based applications, like email accounts.

• Circuit-level firewalls

The circuit-level firewall is a software program that verifies the validity of a message sent to a network through the ‘Transmission Control Protocol (TCP).’ Each TCP has a unique connection protocol that allows a website to transmit messages via a website packet. The circuit-level firewall scans the TCP according to the networks’ ACL. This firewall helps clients who require a fast internet connection to finish work.

• Unified threat management firewalls

This firewall is also known as a UTM firewall. It is a hardware system that combines multiple security devices, including anti-virus software and a VPN server. The UTM prevents a substantial number of security issues from affecting the system. This firewall can help organisations to streamline all network-based activities that require a firewall. It is more cost-effective than other devices.

• Next-generation firewalls

This hardware firewall device manages network packet transmission and VPN servers. Their functionality is not different from a traditional firewall, but they can also analyse each website component in-depth. Which means they can block more harmful materials from entering a computer system. This type of firewall can also manage application data more effectively, meaning the packets to be rejected and the ones that should be allowed depending on where they come from. This firewall is suitable for a client who stores confidential information, as it helps network security and increases protection capability.

Steps involved installing a network firewall

Step 1: Choose a firewall: Choosing a firewall that benefits the system and is suitable for the required needs is crucial. It is important to consider the client’s requirements and day-to-day activities to protect their networks better.

Step 2: Secure the device: After the hardware is installed, it is crucial to secure the device to prevent cyber-attacks and ensure the information is kept safe from being breached or stolen.

Step 3: Devise firewall zones: Consider creating firewall zones to maximise network security, as each zone contains different access protocols.

Step 4: Implement a firewall policy: Collaborate with the client to determine the most effective way to configure ACLs for each firewall zone.

Step 5: Test the firewall: Set up an environment to evaluate whether a firewall is functional and can apply ACL rules correctly. Consider using a vulnerability scanning procedure, which involves discovering potential areas in a network that an outside agent.

Step 6: Update the device: After installing and testing a device successfully, you can begin managing the day-to-day requirements of a firewall. Check its activity history daily to see if an unexpected event occurred and update all software components as necessary.