Internet Protocol Version 6 - IPv6

IPv6 or Internet Protocol Version 6 is the next generation protocol for the Internet. It's designed to provide several advantages over current Internet Protocol Version 4 (or IPv4). The main motivation for the redesign of the Internet Protocol was IPv4 address exhaustion, anticipated after the Internet experienced broad acceptance outside of the academic and research environments that created it. IPv6 is designed by IETF (Internet Engineering Task Force) Both IPv6 and IPv4 define network layer protocol i.e., how data is sent from one computer to another computer over packet-switched networks such as the Internet.

Specifically, IPv6 contains addressing and control information to route packets for the next generation Internet. We believe that the expansion of the Internet is important and upgrades are sometimes warranted. Gathering information concerning every aspects of IPv6 we would hope to provide knowledge about this technology so everyone can benefit. It is therefore also called the Next Generation Internet Protocol .

IPv6 is documented in several RFCs (or request for comments) starting from RFC 2460. Although IPv6 is the successor of IPv4, both protocol versions will continue to be data-oriented protocols for the Internet in the coming years.

IPv4 uses 32 bits for an Internet Protocol address, and can support approximately 4 billion addresses, IPv6 uses a 128-bit address and the new address space supports 2¹²⁸ (3.4×1038) addresses.

IPv6 does not implement interoperability features with IPv4, and creates essentially a parallel, independent network. Exchanging traffic between the two networks requires special translator gateways, but modern computer operating systems implement dual-protocol software for transparent access to both networks.

IPv6 Categories:

IPv6 addresses are broadly classified into three categories:

1) Unicast addresses A Unicast address acts as an identifier for a single interface. An IPv6 packet sent to a Unicast address is delivered to the interface identified by that address.

2) Multicast addresses A Multicast address acts as an identifier for a group/set of interfaces that may belong to the different nodes. An IPv6 packet delivered to a Multicast address is delivered to the multiple interfaces. 

3) Anycast addresses Anycast addresses act as identifiers for a set of interfaces that may belong to the different nodes. An IPv6 packet destined for an Anycast address is delivered to one of the interfaces identified by the address.

IPv6 Address Notation 

IPv6 addresses are denoted by eight groups of hexadecimal quartets separated by colons in between them.

Following is an example of a valid IPv6 address: 2001:cdba:0000:0000:0000:0000:3257:9652 

Any four-digit group of zeroes within an IPv6 address may be reduced to a single zero or altogether omitted. Therefore, the following IPv6 addresses are similar and equally valid:

2001:cdba:0000:0000:0000:0000:3257:9652
2001:cdba:0:0:0:0:3257:9652
2001:cdba::3257:9652

The URL for the above address will be of the form:

http://[2001:cdba:0000:0000:0000:0000:3257:9652]/