TCP/IP Configuration and Management Manual

NonStop TCP/IP Processes and Protocols
TCP/IP Configuration and Management Manual—427132-004
B-3
Addressing
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Assigned Internet addresses are Class A, B, or C depending on the value of the
network address. If your LAN is standalone or private, your LAN administrator can
choose a private set of Internet addresses. In that case, typical use calls for all Class A
addresses.
As shown in Figure B-1, the class of the Internet address determines how the 32 bits
are divided between the network address and the local address.
A Class A address consists of a one-octet network address and a three-octet local
address. The high-order bit of the network address is always 0; therefore, the first octet
is a number in the range 0 through 127 (%H00 through %H7F). So, only 128 Class A
Figure B-1. Internet Address Format
Class A
Address
0 * 8 16 24 31Bit
Class B
Address
0 * 8 16 24 31Bit
Class C
Address
0 * 8 16 24 31Bit
10
11
0
Network
Address
Local Address
Network Address Local Address
Network Address Local Address
015VST .VSD
Legend
* Note: Bit 0 is the most significant bit.
0 *
8162431
Bit
Class D
Address
0 * 8 16 24 31Bit
11
Multicast ID
0 *
8162431
Bit
10
Class E
Address
0 * 8 16 24 31Bit
11
Reserved for Future Use
0 *
8162431
Bit
101