HP Jetdirect J7949e Administrator's Manual page 208

IP Address Structure and Class
An IP address is comprised of 32 bits of information and divided
into 4 sections containing 1 byte each section or 4 bytes total:
xxx.xxx.xxx.xxx
For efficiency in routing, networks were broken down into three
classes, so routing can begin simply by identifying the leading
byte of information in the IP address. The three IP addresses
that InterNIC assigns are class A, B, and C. The network class
determines what each of the four IP address sections identify as
shown in Table
Table A.1 IP Address Class Format
Class First Address
Byte xxx.
A Network.
B Network.
C Network.
As illustrated in
bit identifier, the address range, the number of each type available,
and the maximum number of hosts each class allows.
Table A.2 Network Class Characteristics
Class Leading
Bit
Identifier
A 0
B 10
C 110
NWW
A.1:
Second
Address
Byte xxx.
Host.
Network.
Network.
Table A.2, each network class differs by the leading
Address Range
0.0.0.0 to
127.255.255.255
128.0.0.0 to
191.255.255.255
192.0.0.0 to
223.255.255.255
Third Address Fourth
Byte xxx. Address
Byte xxx
Host. Host
Host. Host
Network. Host
Maximum
Number of
Networks in the
Class
126
16,382
Over 2 Million
TCP/IP Overview 208
Maximum
Hosts in the
Network
Over 16 Million
65,534
254