Which of the following protocols encapsulates an IP packet with an additional IP header?

A.
SFTP

B.
IPSec

C.
HTTPS

D.
SSL

Explanation:
Authentication Header (AH) is a member of the IPsec protocol suite. AH operates directly on top of IP, using IP protocol number 51.
Incorrect Answers:
A: The SSH File Transfer Protocol (also Secure File Transfer Protocol, or SFTP) does not encapsulate IP packets with an additional IP header.
SFTP is a network protocol that provides file access, file transfer, and file management functionalities over any reliable data stream.
C: HTTPS does not add an extra IP header to IP packages. Technically, HTTPS is not a protocol in and of itself; rather, it is the result of simply layering the
Hypertext Transfer Protocol (HTTP) on top of the SSL or TLS protocol, thus adding the security capabilities of SSL/TLS to standard HTTP communications.
D: SSL does not encapsulate IP packets with an additional IP header. Secure Sockets Layer (SSL) is used to establish a secure communication connection
between two TCP-based machines.

Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, Sixth Edition, Sybex, Indianapolis, 2014, pp 75, 76, 268-269, 274, 274-275