Which firewall type uses deep packet inspection to analyze content?

The application firewall is specifically designed to operate at the application layer of the OSI model, which allows it to understand and filter traffic based on the applications and services that generate the data. By performing deep packet inspection, this type of firewall is capable of analyzing the complete content of the data packets—not just their headers. This enables it to identify and block attacks based on the actual content being transmitted, rather than simply filtering out packets based on source or destination addresses.

This capability is particularly important for identifying and mitigating application-level threats, such as SQL injection or cross-site scripting attacks, which are often hidden within the application data itself. Because application firewalls can interpret higher-level protocols, they provide an additional layer of security that goes beyond the capabilities of standard firewalls, which may not inspect the full data payload of packets.

Understanding the role of an application firewall in this context highlights its importance in a comprehensive security strategy for protecting critical infrastructure.