What is the characteristic of a stateful inspection firewall regarding deep and shallow inspection?

Stateful inspection firewalls are designed to monitor the state of active connections and make decisions based on the context of the traffic flows, rather than just the individual packets. This capability allows stateful inspection firewalls to perform shallow inspection by analyzing the headers of packets to gather quick information about the traffic, such as source and destination addresses, ports, and the protocol used.

In addition to shallow inspection, many stateful inspection firewalls have the ability to perform deep inspection, which involves a more thorough examination of the packet contents. This includes inspecting the payload of the packets for more complex analysis, such as identifying specific applications or detecting malicious content.

The correct answer reflects that while all stateful inspection firewalls perform shallow inspection as a basic functionality, not all of them are limited to that; many also have the capability to conduct deep inspection, enhancing their ability to secure the network by understanding not just the connection states but also the data being transmitted. This is particularly important in modern security environments where threats can be hidden within legitimate traffic.