What Is a Firewall?
A firewall creates a barrier between an external network and a protected internal one. It monitors the data packets that enter or leave a network, judging each against a set of rules and denying access to any based on those criteria.
Firewalls can be hardware appliances, software-based, or hosted in the cloud. They are often combined with anti-virus and anti-malware solutions to deliver comprehensive protection from advanced threats like viruses, backdoors, Trojan horses, phishing attacks, macros, remote logins, and unauthorized activity.
Modern firewall technology incorporates next-generation CASB capabilities to secure SaaS applications in real time in a branch office setting. They offer granular visibility and enforcement to ensure that IoT and IT devices are safe from external threats while meeting the unique security requirements of distributed workforces.
Firewalls are typically able to determine whether or not a packet is harmful based on a series of pre-configured rules that are constantly changing. They can employ a variety of methods, including packet filtering, stateful inspection, and dynamic host configuration. In the case of stateful inspection, a firewall will analyze each packet in its entirety to determine whether or not it contains dangerous data or patterns of behavior. This offers more thorough protection, but can have a significant impact on network performance. As threats evolve, it is important to have a regular schedule for reviewing and updating firewall rules to keep pace with the latest vulnerabilities and malicious activities. Additionally, log management tools can help identify suspicious activities and suspicious behavior based on events recorded in firewalls.