Systems Security Certified Practitioner – SSCP – Question0939 - Systems Security Certified Practitioner

Which IPSec operational mode encrypts the entire data packet (including header and data) into an IPSec packet?

A. Authentication mode
B. Tunnel mode
C. Transport mode
D. Safe mode

Correct Answer: B

Explanation:

In tunnel mode, the entire packet is encrypted and encased into an IPSec packet.
In transport mode, only the datagram (payload) is encrypted, leaving the IP address visible within the IP header.
Authentication mode and safe mode are not defined IPSec operational modes.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 96).