The IP addressing scheme is integral to the process of routing IP datagrams through an internetwork. Each IP address has specific components and follows a basic format. These IP addresses can be subdivided and used to create addresses for subnetworks.
Each host on a TCP/IP network is assigned a unique 32-bit logical address that is divided into two main parts: the network number and the host number. The network number identifies a network and must be assigned by the Internet Network Information Center (InterNIC) if the network is to be part of the Internet.
IP Address Format
The 32-bit IP address is grouped eight bits at a time, separated by dots, and represented in decimal format (known as dotted decimal notation). Each bit in the octet has a binary weight (128, 64, 32, 16, 8, 4, 2, 1). The minimum value for an octet is 0, and the maximum value for an octet is 255. illustrates the basic format of an IP address.
IP Address Classes
IP addressing supports five different address classes: A, B,C, D, and E. Only classes A, B, and C are available for commercial use
Each host on a TCP/IP network is assigned a unique 32-bit logical address that is divided into two main parts: the network number and the host number. The network number identifies a network and must be assigned by the Internet Network Information Center (InterNIC) if the network is to be part of the Internet.
IP Address Format
The 32-bit IP address is grouped eight bits at a time, separated by dots, and represented in decimal format (known as dotted decimal notation). Each bit in the octet has a binary weight (128, 64, 32, 16, 8, 4, 2, 1). The minimum value for an octet is 0, and the maximum value for an octet is 255. illustrates the basic format of an IP address.
IP Address Classes
IP addressing supports five different address classes: A, B,C, D, and E. Only classes A, B, and C are available for commercial use
Table Reference Information About the Five IP Address Classes
IP Address Class | Format | Purpose | High-Order Bit(s) | Address Range | No. Bits Network/Host | Max. Hosts |
|---|---|---|---|---|---|---|
A | N.H.H.H1 | Few large organizations | 0 | 1.0.0.0 to 126.0.0.0 | 7/24 | 167772142 (224 - 2) |
B | N.N.H.H | Medium-size organizations | 1, 0 | 128.1.0.0 to 191.254.0.0 | 14/16 | 65534 (216 - 2) |
C | N.N.N.H | Relatively small organizations | 1, 1, 0 | 192.0.1.0 to 223.255.254.0 | 21/8 | 254 (28 - 2) |
D | N/A | Multicast groups | 1, 1, 1, 0 | 224.0.0.0 to 239.255.255.255 | N/A (not for commercial use) | N/A |
E | N/A | Experimental | 1, 1, 1, 1 | 240.0.0.0 to 254.255.255.255 | N/A | N/A |
IP address formats A, B, and C are available for commercial use.
