Internet Protocol address

Last updated Jan 30, 2023

• Technologies
• Networking

An 4-byte (i.e., 32-bit) identifier for a network device typically assigned by another more prominent network device that identifies the device in the network using the internet protocol. Typically has two components to it, namely the:

• network identifier; and
• host identifier.

Usually expressed in a decimal format of a byte per section, separated by periods. IP addresses therefore range from 0.0.0.0 to 255.255.255.255 (256 values per byte).

IP addresses have different classifications based on the how many bits the network identifier occupies. There are in particular three classes, namely:

• Class A addresses (1-byte network addresses, ranging from 0.0.0.1 to 127.255.255.254);
• Class B addresses (2-byte network addresses, ranging from 128.0.0.1 to 191.255.255.254); and
• Class C addresses (3-byte network addresses, ranging from 192.0.0.1 to 223.255.255.254).

For each class, the very first and last address are used specially for identifying the network and broadcasting. For example, for a range of 192.168.1.0 to 192.168.1.255, 192.168.1.0 is used for identifying the network and 192.168.1.255 is used for broadcasting. The rest is usable by other network devices.

Usually just used in internal networks. Not routable through the internet and will therefore not work in the internet, and must be converted to a public IP address instead. Each IP address class has a range dedicated to private IP addresses, namely:

• 10.0.0.0 to 10.255.255.255 for Class A addresses;
• 172.16.0.0 to 172.31.255.255 for Class B addresses; and
• 192.168.0.0 to 192.168.255.255 for Class C addresses.

To translate or map a private address to or fro a public address, network address translation (NAT) can be used.

IP addresses can be static or dynamic, and they are assigned via the Dynamic Host Configuration Protocol (DHCP).

# Binding of IP address with MAC address

IP addresses are often bound together with MAC addresses via the Address Resolution Protocol (ARP) and, in the past, the Reverse Address Resolution Protocol (RARP).