Class B addresses

In class B, the first two octets (/16 prefix) are used to represent the network portion, and the remaining two octets are used to represent host addresses. It is obvious that in class B, the number of networks is larger than in class A, and the numbers of hosts per network is smaller than in class A. For that reason, class B is designed to support medium-to-large organizations that prefer to have a considerable number of networks with up to 65,534 available host addresses per network. The following table provides information about class B:

Class	Range	Maximum Number of Networks	Number of Hosts per Network	Leftmost Bit
B	128.0.0.0 - 191.255.255.255*	214 = 16,384	216 - 2 = 65,534	10

* IP addresses from 169.254.0.0 to 169.254.255.255 are reserved for APIPA.