RX3141 User’s Manual | Chapter 12. IP Addresses, Network Masks, and Subnets |
12 IP Addresses, Network Masks, and Subnets
12.1 IP Addresses
This section pertains only to IP addresses for IPv4 (version 4 of the Internet Protocol). IPv6 addresses are not covered.
Note | This section assumes basic knowledge of binary numbers, bits, | |
and bytes. For details on this subject, see Appendix 12. | ||
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IP addresses, the Internet's version of telephone numbers, are used to identify individual nodes (computers or devices) on the Internet. Every IP address contains four numbers, each from 0 to 255 and separated by dots (periods), e.g. 20.56.0.211. These numbers are called, from left to right, field1, field2, field3, and field4.
This style of writing IP addresses as decimal numbers separated by dots is called dotted decimal notation. The IP address 20.56.0.211 is read "twenty dot
IP addresses have a hierarchical design similar to that of telephone numbers. For example, a
Similarly, IP addresses contain two kinds of information.
fNetwork ID
Identifies a particular network within the Internet or Intranet
fHost ID
Identifies a particular computer or device on the network
The first part of every IP address contains the network ID, and the rest of the address contains the host ID. The length of the network ID depends on the network's class (see following section). Table 12.1 shows the structure of an IP address.
Table 12.1. IP Address Structure
| Field1 | Field2 | Field3 |
| Field4 |
|
|
|
|
|
|
Class A | Network ID |
| Host ID |
|
|
Class B | Network ID |
| Host ID | ||
Class C |
| Network ID |
|
| Host ID |
Here are some examples of valid IP addresses:
Class A: 10.30.6.125 (network = 10, host = 30.6.125)
Class B: 129.88.16.49 (network = 129.88, host = 16.49)
Class C: 192.60.201.11 (network = 192.60.201, host = 11)
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