Certified Ethical Hacker (CEH v13) — Question 51

Andrew is an Ethical Hacker who was assigned the task of discovering all the active devices hidden by a restrictive firewall in the IPv4 range in a given target network. Which of the following host discovery techniques must he use to perform the given task?

Answer options

• A. UDP scan
• B. ARP ping scan
• C. ACK flag probe scan
• D. TCP Maimon scan

Correct answer: B

Explanation

The correct answer is B, ARP ping scan, because it operates at the data link layer and can identify active devices on a local network even when a firewall is present. The other options, while useful for various scanning purposes, are less effective in penetrating restrictive firewall settings and may not reliably reveal hidden devices.