Correct Answer: B
Explanation/Reference:
Explanation:
IPSec works at the network layer, not at the transport layer.
Incorrect Answers:
A: IPSec protects networks by authenticating and encrypting each IP packet of a communication session.
C: IPSec protects against man-in-the-middle attacks by combining mutual authentication with shared, cryptography-based keys.
D: IPSec uses cryptography-based keys, shared only by the sending and receiving computers, to create a cryptographic checksum for each IP packet. The cryptographic checksum ensures that only the computers that have knowledge of the keys could have sent each packet. This products against spoofing.
References:
Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 1360