Certified Ethical Hacker (CEH v10) — Question 102

What does a firewall check to prevent particular ports and applications from getting packets into an organization?

Answer options

• A. Transport layer port numbers and application layer headers
• B. Presentation layer headers and the session layer port numbers
• C. Network layer headers and the session layer port numbers
• D. Application layer port numbers and the transport layer headers

Correct answer: A

Explanation

The correct answer is A because firewalls primarily operate at the transport and application layers, examining port numbers and headers to control traffic. Options B, C, and D include incorrect layer references or combinations that do not align with the firewall's functionality in packet filtering.