Which of the following network architecture concepts is used to securely isolate at the boundary
between networks?

A.
VLAN

B.
Subnetting

C.
DMZ

D.
NAT

Explanation:
A demilitarized zone (DMZ) is an area of a network that is designed specifically for public users to access.
The DMZ is a buffer network between the public untrusted Internet and the private trusted LAN. Often a
DMZ is deployed through the use of a multihomed firewall.
Incorrect Answers:
A: A virtual local area network (VLAN) is a hardware-imposed network segmentation created by switches.
VLANs are used for traffic management. VLANs can be used to isolate traffic between network segments.B: Subnetting is a dividing process used on networks to divide larger groups of hosts into smaller
collections.
D: NAT converts the IP addresses of internal systems found in the header of network packets into public
IP addresses. A demilitarized zone (DMZ) is an area of a network that is designed specifically for public
users to access.

Stewart, James Michael, CompTIA Security+ Review Guide, Sybex, Indianapolis, 2014, pp. 23, 39