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Understanding Ipv6

As the world says goodbye to IPv4, we are welcoming the new generation of IP, IPv6. There is no doubt as this was estimated by IANA (Internet Assigned Numbers Authority), that version 4 of IP addresses will be exhausted in Feb, 2011. The Internet is growing rapidly making it hard for IPv4 to sustain the growth. Because of this challenge, we require version 6 of IP addresses (IPv6).

What is IPv6? (RFC 2460)

Being a successor to the first addressing infrastructure, IPv6 has a 128 Bit length contrary to its predecessor IPv4 which had 32 Bits. IPv6 has eight octets with each octet containing 4 HEX characters and classified as a group separated by full colons. Moving from 32 Bits to 128 Bits is said to create an almost infinite number of IP addresses (3.4×10 to power 38).

The header for IPv6 has a payload of 16 bits making it suitable for devices with low processing power. The version of IP addresses also contains a new feature known as Flow Labeling Capability, which enables labeling of packets to a particular flow that requires special handling. Although the version seems long, it can be simplified by dropping leading zeros and replacing groups of consecutive zeros with two colons as below:

1. Raw IPv6

2001:0050:0000:0000:0000:0AB4: 1E2B:98AA

2. Eliminate groups of consecutive zeros only once and add full colons.


3. Drop leading zeros

2001:50::AB4:1E2B:98AA (Neat IPv6)

Modes of communication in IPv6

To make IPv6 more efficient, broadcast messages were eliminated and replaced by multicast (One-to-many). Communication is based only on three channels.

Unicast – one-to-one

Multicast – one-to-many

Any-cast – one-to-closest

Types of addresses in IPv6

Link-Local Scope Address – used at layer two domains (Originally broadcast domain in IPv4)

Unique/Site-Local Scope Address – used at an organizational level (Comparable to private IPv4 addresses)

Global Scope Address – used to access the Internet. (IPv4 Public addresses)

IPv4 and IPv6 can be run together on the same network using protocol stacking. To understand more about IPv6 read its Request for Comments at:

Why do we need IPv6?

New network devices that require IP addresses are on the rise. An example is a single user with a laptop, smartphone, a PC and a netbook. These are four public IPs if the person has to connect with a static IP with no NAT. Multiply that with the population that owns or are planning to acquire these devices.

NAT (Network Address Translation) is seen as an obstacle to innovation; therefore, we are shifting focus to a generation where we require mobility as well as security and a version of IP addresses that will support the next generation of devices.


IPv6 Summit- What is IPv6?

WhatIsMyIPAddress.com- What is IPv6?

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