Main border firewalls rarely use stateful packet inspection.

• A. True
• B. False
• C. Sometimes
• D. Not sure

Answer: (B)

Border firewalls at the network edge rely on stateful inspection to make smart, context-aware decisions about traffic. Stateful packet inspection tracks active connections, so each incoming packet is checked against the state of its corresponding session (such as TCP handshakes and NAT mappings). This enables the firewall to determine whether traffic is expected, allowed, or part of a legitimate return flow, and it helps detect anomalies like unexpected packets or sequence issues. Because handling protocols that depend on session state is essential for secure and correct filtering at the border, stateful inspection is a standard capability rather than a rarity. There can be ultra-high-speed or specialized setups that emphasize stateless filtering for performance, but in typical modern deployments, border firewalls use stateful inspection by default.