What Is a Firewall?
A firewall acts as a shield that protects your device, network, and information from cyberattacks. It observes and filters incoming and outgoing network traffic, adhering to security policies set by your organization. Firewalls are also used by organizations to manage employee remote access to the internet.
Firewalls can be deployed in hardware or software form. Most devices, such as computers and tablets, have a firewall built in that can be activated for added protection from malware. Typically, these firewalls are configured with default settings that are less restrictive than what would be best for the individual device or system. For optimal protection, you should consider installing separate firewall software from an established hardware or software vendor.
Different types of firewalls use multiple methodologies and technologies to detect malicious activity based on context and data packet content. For example, packet filtering reads the contents of data packets that move between a private network and the internet to ensure only valid communications are allowed through. This technique provides more security than circuit monitoring but takes a toll on networking speeds.
Stateful inspection firewalls read data packets at the network, transport, and application layers to determine whether they match a list of established connections. These firewalls offer a great deal of protection against denial-of-service attacks but can be vulnerable to advanced threats like malware.
Network administrators should regularly review and update firewall rules to prevent them from becoming obsolete or susceptible to new cybersecurity threats. Additionally, it is important to make sure that all device and system updates are being installed correctly so that potential vulnerabilities are not exposed.