Which firewall type is described as inspecting outbound traffic and blocking nonstandard application traffic such as IRC on port 80?

• A. Packet-filtering firewall
• B. NAT firewall
• C. Application firewall
• D. Stateful firewall

Answer: (C)

An application-layer inspection is needed here. An application firewall analyzes the actual application protocols and payload, not just the network headers. This lets it see and control what applications are allowed to use the network, so it can block nonstandard traffic like IRC even when it’s using port 80. In contrast, a packet-filtering firewall only looks at headers (source/destination, port, protocol) and can’t reliably distinguish IRC from ordinary HTTP on the same port; a NAT firewall mainly translates addresses without inspecting content; and a stateful firewall tracks connections but still relies largely on ports and protocols rather than recognizing and filtering by application type. So, the ability to inspect outbound traffic at the application level and block disguised or nonstandard application traffic makes an application firewall the best fit.