Which of the following is an extension to Network Address Translation that permits multiple devices providing
services on a local area network (LAN) to be mapped to a single public IP address?

A.
IP Spoofing

B.
IP subnetting

C.
Port address translation

D.
IP Distribution

Explanation:
Port address translation (PAT) is an implementation of Network Address Translation. PAT is a mechanism for
converting the internal private IP addresses found in packet headers into public IP addresses and port numbers
for transmission over the Internet. PAT supports a many-to-one mapping of internal to external IP addresses by
using ports.
Incorrect Answers:
A: IP Spoofing does not involve mapping of IP addresses. IP spoofing is the creation of Internet Protocol (IP)
packets with a forged source IP address, with the purpose of concealing the identity of the sender or
impersonating another computing system
B: IP subnetting is the practice of dividing a network into two or more networks.
D: The distribution of IP addresses does not involve mapping of IP addresses.

Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 606