What is the subnet portion of the IP address and what is the subnet mask for the following:

a. 12.1.0.0/16

b. 12.1.0.0/24

c. 12.1.0.0/20

d. 12.1.0.0/28

F. You might be wondering how the first bytes for each address range were picked. Why do you think

Class A’s first byte is 1–126, Class B’s byte is 128–191, and Class C’s byte is 192–223?