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Saturday, 9 June 2012

What is IPv6 and why do we need it?


The Internet operates by transferring data between networks in packets. In order to communicate and send/receive packets of data, each host, computer or other device connected to the Internet must be identified by a unique IP address. 
IPv4 has approximately four billion IP addresses (the sequence of numbers assigned to each Internet-connected device). 
The explosion in the number of people, devices, and web services on the Internet means that IPv4 is running out of space. IPv6, the next-generation Internet protocol which provides more than 340 trillion, trillion, trillion addresses, will connect the billions of people not connected today, allow a huge range of devices to connect directly with one another, and help ensure the Internet can continue its current growth rate indefinitely. 
Both IPv4 and IPv6 (and many other protocols at the core of the Internet) were developed by the Internet Engineering Task Force (IETF).

How will this impact my everyday Internet usage?

Most Internet users will not be affected. Internet users should enjoy uninterrupted service. In rare cases, users may still experience connectivity issues when visiting participating Websites. Users can visit an IPv6 test site to check if their connectivity will be impacted. If the test indicates a problem, they can disable IPv6 or ask their ISPs to help fix the problem. A more detailed network connectivity check is also available.

Comparison to IPv4

Larger address space


Decomposition of an IPv6 address into its binary form The main advantage of IPv6 over IPv4 is its larger address space. The length of an IPv6 address is 128 bits, compared to 32 bits in IPv4. The address space therefore has 2128 or approximately 3.4×1038 addresses.

"If the capacity of IPv4 is described as a golf ball, then the comparative size for IPv6is like the sun," said executive chairman of the American Registry for Internet NumbersJohn Curran

Multicasting

Multicasting, the transmission of a packet to multiple destinations in a single send operation, is part of the base specification in IPv6. In IPv4 this is an optional although commonly implemented feature.IPv6 multicast addressing shares common features and protocols with IPv4 multicast, but also provides changes and improvements by eliminating the need for certain protocols.

Privacy

Like IPv4, IPv6 supports globally unique static IP addresses, which can be used to track a single device's Internet activity. Most devices are used by a single user, so a device's activity is often assumed to be equivalent to a user's activity. This is a cause for concern to anyone who has political, social, or economic reasons for keeping their Internet activity secret.

Address format

An IPv6 address is represented by 8 groups of 16-bit hexadecimal values separated by colons (:). For example:
2001:0db8:85a3:0000:0000:8a2e:0370:7334