What is IPv6 address?

The original internet addressing system is called 'Internet Protocol, Version 4' (IPv4), and it has numbered the computers of the Internet successfully for years. By employing 32-bits of recombined digits, IPv4 has a maximum of 4.3 billion possible addresses.

Now, while 4.3 billion addresses might seem plentiful, the Internet was going to exceed this number of devices by the end of 2012. Every computer, every cell phone, every iPad, every printer, every Playstation, and even soda machines require an IP address. There are not enough IPv4 addresses for all these devices!

Good news: a new internet addressing system is here, and it will fill our need for more computer addresses.

Internet Protocol version 6 (IPv6) is currently being rolled out across the globe, and its enlarged addressing system will fix the limitation of IPv4. IPv6 uses 128 bits instead of 32 bits for its addresses, creating 3.4 x 10^38 possible addresses (that is a 'trillion-trillion-trillion'; undecillion' is an obscure term that describes this impossibly large number).

These trillions of new IPv6 addresses will meet the internet demand for the foreseeable future.

What is IPv6?

A new Internet addressing system Internet Protocol version 6 (IPv6) is being deployed to fulfill the need for more Internet addresses.

IPv6 (Internet Protocol Version 6) is also called IPng (Internet Protocol next generation) and it is the newest version of the Internet Protocol (IP) reviewed in the IETF standards committees to replace the current version of IPv4 (Internet Protocol Version 4).

IPv6 is the successor to Internet Protocol Version 4 (IPv4). It was designed as an evolutionary upgrade to the Internet Protocol and will, in fact, coexist with the older IPv4 for some time. IPv6 is designed to allow the Internet to grow steadily, both in terms of the number of hosts connected and the total amount of data traffic transmitted.

IPv6 is often referred to as the "next generation" Internet standard and has been under development now since the mid-1990s. IPv6 was born out of concern that the demand for IP addresses would exceed the available supply.

Advantages of IPv6?

The IP layer of the TCP/IP protocol stack is the most crucial piece of the whole Internet architecture. However, within ten years of IP going mainstream in the 1980s, the limitations of IPv4 in terms of scalability and capability became obvious. IPv4 requires several add-ons like ICMP and ARP to function. By the mid-1990s, a replacement scheme was developed. The move to IPv6 is necessary to accommodate the explosion of Internet requirements, Internet technology profile mandates that access via IPv4 and access via IPv6 have to coexist.

There are also other important technological changes in IPv6 that will improve the IP protocol:
  • Elimination of NAT(Network Address Translation) to extend address space from 32 to 128 bits
  • Stateless address auto-configuration for easier network administration
  • No more private address collisions
  • Better multicast routing
  • Improved header structure with less processing overhead
  • Simplified, more efficient routing without fragmenting packets
  • Built-in Quality of Service (QoS), also called "flow labeling" that distinguishes delay-sensitive packets
  • Built-in authentication and privacy support (IPsec)
  • Flexible options and extensions
  • Easier administration (say good-bye to DHCP)

Difference between IPv4 and IPv6 addresses

One of the differences between IPv4 and IPv6 is the appearance of the IP addresses. IPv4 uses four 1 byte decimal numbers, separated by a dot (i.e., while IPv6 uses hexadecimal numbers that are separated by colons (i.e. fe80::d4a8:6435:d2d8:d9f3b11).

  • IPv6 address consists of 128 bits, while an IPv4 address consists of only 32.
  • IPv6 has a lot more usable addresses compared to IPv4.
  • IPv6 is better suited to mobile networks than IPv4.
  • IPv6 addresses are represented in a hexadecimal, colon-separated notation(i.e. fe80::d4a8:6435:d2d8:d9f3b11), while IPv4 address use the dot-decimal notation (
  • IPv6 allows for bigger payloads than what is allowed in IPv4.

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