More on IP addressing

The Internet is a worldwide system of data communication based on the concept of ‘packet networks’. Information is exchanged over these networks as sequences of data, in units called ‘packets’. IP packets are highly structured and include a ‘header’, which includes the source and destination addresses of two systems that are communicating over the Internet Protocol.

IP addresses can be expressed in binary, decimal, or hexadecimal form. These address representations are frequently used to configure end systems, in routing infrastructure, and all IP active devices.

IPv4IPv6
32-bit number (232)128-bit number (2128)
Address space: around 4 billionAddress space: 340 trillion, trillion, trillion
e.g. 202.12.29.142e.g. FE38:DCE3:124C:C1A2:BA03:6745:EF1C:683D
4 groups of numbers, 8 bits per group16 bits per group, expression compressed
256 combinations65,536 combinations

Diagram: Typical structure of IPv4 and IPv6 addresses

More about IPv4 and IPv6

IPv4 addresses are commonly expressed as four groups of decimal values separated by dots, known as “dotted quad notation”. Dotted quad notation is a method of writing binary values (1,0) in groups of eight bits (octets).

IPv6 addresses are represented differently because they are much longer than IPv4 addresses.

The IPv6 address size is 128-bits long, or 16 8-bit octets. This represents an astronomical increase in address size from 4,294,967,296 seen in IPv4 to over 340 trillion, trillion, trillion. That’s enough addresses for many trillions of addresses to be assigned to every person on Earth.

IPv6 in-depth