Cisco Networking Essentials

Identifying IP Address Types

As you learned in Chapter 6, “Numbering Systems,” IP addresses are 32 bits in length when expressed in binary. When humans work with IP addresses, however, it is usually done in what is called dotted decimal format. An IP address in this format looks like the following:

192.168.5.3

This format is called dotted decimal because the sections, or fields, are divided by dots, and the values are expressed in decimal instead of binary. Each of the four fields is called an octet because each section can be expressed in binary format by using 8 bits. So to convert 192.168.5.3 to its binary format, each decimal number would be converted to its equivalent in binary. Because each section is 8 bits in length, the result would ...