Dotted decimal notation represents a 32-bit IPv4 address as four decimal octets separated by periods. Each octet contains 8 bits and ranges from 0 to 255, making addresses easier to read than binary strings. section 7.3.1 section 7.4
Read an IPv4 address by separating its representation into these related parts:
- The four octets correspond to four groups of 8 bits in the 32-bit address. section 7.3.1
- A prefix length such as /24 identifies the network portion; the remaining bits form the host portion. section 7.3.1
- Hosts on the same LAN share the network portion but use unique host portions. section 7.3.1
Example: 192.168.100.100/24
The address contains the octets 192, 168, 100, and 100. With /24, the first three octets represent the network portion, 192.168.100, while the final octet identifies the host. Other hosts on that LAN could use 192.168.100.1 or 192.168.100.178. section 7.3.1
Figure 7.7 An IPv4 address written in both dotted decimal and binary. The 32-bit address is split into four octets consisting of 8 bits each. The address is divided into two parts: the network portion and the host portion. The prefix length indicates the size of the network portion in bits, and the remainder is the host portion.
Compare the four dotted-decimal octets with their binary values and see how the prefix length divides network and host portions. section 7.3.1
