The management and data plane
There are two main planes that make up a firewall, the data plane and the management plane, which are physical or logical boards that perform specific functions. All platforms have a management plane. Larger platforms like the PA-5200 come with 2 to 3 data planes and the largest platforms have replaceable hardware blades (line cards) that have up to 3 data plane equivalents per line card and can hold up to 10 line cards. The smaller platforms like the PA-220 only have the one hardware board that virtually splits up responsibilities among its CPU cores.
The management plane is where all administrative tasks happen. It serves the web interfaces used by the system to allow configuration, provide URL filtering block pages, and serve the client VPN portal. It performs cloud lookups for URL filtering and DNS security, and downloads and installs content updates onto the data plane. It also performs the logic part of routing and communicates with dynamic routing peers and neighbors. Authentication, User-ID, logging, and many other supporting functions that are not directly related to processing packets.
The data plane is responsible for processing flows and performs all the security features associated with the next-generation firewall. It scans sessions for patterns and heuristics. It maintains IPSec VPN connections and has hardware offloading to provide wire-speed throughputs. Due to its architecture and the use of interconnected specialty chips, all types of scanning can happen in parallel as each chip processes packets simultaneously and reports its findings.
A switch fabric enables communication between planes so the data plane can send lookup requests to the management plane, and the management plane can send configuration updates and content updates.
Another important feature is the ability to identify users and apply different security policies based on identity or group membership.
