A security administrator is creating a subnet on one of the corporate firewall interfaces to use as a DMZ which is expected to accommodate at most 14 physical
hosts. Which of the following subnets would BEST meet the requirements?
A.
192.168.0.16 255.25.255.248
B.
192.168.0.16/28
C.
192.168.1.50 255.255.25.240
D.
192.168.2.32/27
25 26 27 28 29 30 31 32
128 64 32 16 8 4 2 1
14 hosts means 2^4=16
Here’s some more details:
Calculation of subnets is 2 to the power of N, n being the amount of bits on the host range (4)(Cidr blocks 32 – 28). This gives us 16 but remember to take off an address for subnet address and broadcast address. This leaves us with 14 host addresses. 2 ^ n – 2
Then to find the valid subnet: 256 – 240 = 16 (192.168.0.16)