Certified Ethical Hacker (CEH v11) — Question 358

Harris is attempting to identify the OS running on his target machine. He inspected the initial TTL in the IP header and the related TCP window size and obtained the following results:

TTL: 64 -

Window Size: 5840 -
What the OS running on the target machine?

Answer options

• A. Windows OS
• B. Mac OS
• C. Linux OS
• D. Solaris OS

Correct answer: C

Explanation

The correct answer is Linux OS because a TTL of 64 and a TCP window size of 5840 are characteristic of Linux systems. On the other hand, Windows typically has a TTL of 128, Mac OS has a different range, and Solaris usually uses a TTL of 255.