What Is a Firewall?
Firewall is a cybersecurity solution that monitors incoming data packets for specific security protocols and then either allows or blocks access to your devices, network, and personal information. While there are new cybersecurity threats emerging all the time, firewalls can help keep cybercriminals at bay by acting as a protective shield for your computers and devices.
Firewalls can come in hardware, software, or as a cloud-based application. Most commercially available firewall products, both hardware and software based, come preconfigured with default configuration settings that may not provide sufficient security. For this reason, it is imperative that you carefully read and understand the documentation that comes with a given firewall product to ensure that the default configuration settings are suitable for your environment.
Packet filtering firewalls operate at a very low level in the TCP/IP protocol stack to compare each packet to a set of rules that define what the device or connection can do on your private network. This is often the least expensive type of firewall, but it can also be less effective against advanced malware that targets the source and destination of individual data packets in a communication flow.
At Digital Equipment Corporation in the late 1980s, Mogul, Reid, and Vixie each had roles in developing the packet-filtering technology that would eventually become the foundation of firewall systems. In 1993, Gil Shwed and Nir Zuk each contributed to the development of a user-friendly firewall product with stateful inspection functionality that was widely adopted in 1994—Check Point’s Firewall-1. This approach can assess the context and state of communications as they move across your private network, which is an improvement over circuit monitoring and network layer filters that only look at a packet’s source and destination.