Which Boolean operator is used with the subnet mask to determine the network portion of an
Internet address?

A.
AND

B.
OR

C.
NOT

D.
NOR

Explanation:
A Boolean AND operation generates a truth table such that if both bits are a one, then result is
one, otherwise the result is zero. When applying the subnet mask, the network portion is
represented by 1 bits and the host is represented by 0 bits. After ANDing the subnet mask with the
IP address, all that will be left is the network portion.
Incorrect Answers:
B: A Boolean OR option generates a truth table such that if both bits are zero, the result is zero,
otherwise the result will be one. Merging the subnet mask with the IP address will not yield the
network ID, the IP address will almost look more like the subnet mask itself.
C: A Boolean NOT operation flips the bit, if it is a zero, it becomes a one, and if a one it becomes a
zero. This is yield a totally corrupted IP address, and will not yield the network ID, nor anything of
use.
D: A Boolean NOR operation is a NOT OR operation that does the OR and the NOT, and will also
produce garbage for an IP address.