ISA/IEC 62443 Cybersecurity Fundamentals Specialist — Question 32

What do packet filter firewalls examine?

Answer options

• A. The packet structure and sequence
• B. The relationships between packets in a session
• C. Every incoming packet up to the application layer
• D. Only the source, destination, and ports in the header of each packet

Correct answer: D

Explanation

The correct answer is D because packet filter firewalls primarily inspect the header information of packets, which includes the source and destination IP addresses and port numbers. Options A and B are incorrect as they refer to aspects that are not analyzed by packet filter firewalls, and option C is incorrect since these firewalls do not examine packets beyond the transport layer.