Difference between IPv4 and IPv6 addresses

As the Internet address system reaches its end, Internet Protocol version 6 (IPv6) is replacing the widely used Internet Protocol Version 4 (IPv4).

Internet Protocol version 4, or IPv4 was designed in 1980s with a maximum of 4.1 billion addresses to send data from one computer to another, but it reaches its end. To solve this, IPv6 is designed by increasing 32-bit to 128-bit address space.

How does an IPv6 address look like ( an example of IPv6)

The IPv6 128-bit address is divided along 16-bit boundaries. 16-bit block in the address converted to hexadecimal and delimited with colons.

2001:0db8:85a3:0000:0000:8a2e:0370:7334.

IPv6 can be simplified by removing the leading zeros within each 16-bit block.

IPv4 vs IPv6 : Difference

• IPv4 addresses are 32-bit numbers, meaning that there are 4.3 billion possible addresses.
• IPv6 addresses are 128-bit numbers, meaning that the number of possible addresses of 340 undecillion.

Example:

• IPv4 address has 4 octets separated by decimals (for example, 59.93.88.169)
• IPv6 uses hexadecimal system and each address is assigned a space of 16 bytes (possibilities of 2¹²⁸ or 3.408 X 10^{38 )} (example – 2001:0db8:85a3:0000:0000:8a2e:0370:7334)

(Credit: Number Resource Organization via cnet.com and wiki)