Certified Ethical Hacker (CEH v8) — Question 1

A circuit level gateway works at which of the following layers of the OSI Model?

Answer options

• A. Layer 5 - Application
• B. Layer 4 – TCP
• C. Layer 3 – Internet protocol
• D. Layer 2 – Data link

Correct answer: B

Explanation

A circuit level gateway functions at Layer 4, which is the Transport layer, primarily handling TCP connections. The other options refer to different layers; Layer 5 is for application-level interactions, Layer 3 is focused on routing and addressing, and Layer 2 deals with data link protocols.