Different Types of Firewalls
Firewall is a network security device that monitors and controls the flow of information between different systems and devices. It performs a quick assessment of each data packet and depending on multiple aspects, like source and destination, it either blocks or allows access to the system. It protects the system from malware, hacking and other cyberattacks and prevents the unauthorized entry of malicious software or data into a company’s network.
Different types of firewalls perform different assessments on data packets at different network levels. For instance, a network layer firewall checks each packet on the basis of preexisting criteria and shields against obvious intrusion attempts. This includes websites laced with malware, hijacking software and unknown connections. Network layer filters can also be customized to add new filter criteria.
Another kind of firewall checks each packet by inspecting the entire data transfer protocol. Circuit-level gateways check the TCP handshake, which is designed to verify that each stage of the transmission is legitimate. These are very resource-efficient and can approve or deny traffic quickly without consuming significant computing resources.
On the other hand, stateful inspection firewalls keep a contextual database of vetted connection and user data to better assess each request. They can also draw on historical traffic records to determine the depth of scrutiny each packet warrants. These offer more granular and advanced protection than packet filters, but they can slow down the processing of requests. This may not always be the best option for businesses relying on high-performance applications or for those that want to maintain bandwidth.