ISC Exam Questions

Which Network Address Translation (NAT) is the MOST con…

Which Network Address Translation (NAT) is the MOST convenient and secure solution?

A.
Hiding Network Address Translation

B.
Port Address Translation

C.
Dedicated Address Translation

D.
Static Address Translation

Explanation:
Port Address Translation (PAT) maps one internal IP address to an external IP address and port number
combination. Thus, PAT can theoretically support 65,536 (2 16 ) simultaneous communications from internal
clients over a single external leased IP address. A company can save a lot of money by using PAT, because
the company needs to buy only a few public IP addresses, which are used by all systems in the network.
Incorrect Answers:
A: NAT maps one internal IP address to one external IP address. Compared to PAT this is pretty bad.
C: There is no NAT implementation called Dedicated Address Translation.
D: Static Address Translation is not convenient as it must be configured manually.

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