“Vasudev Kutumbakam”- The whole world is one family, which was predicated in the past by famous Indian Spiritual Personality which seems to be completely achieved today through Internet, World have larger numbers of Internet user, for resource sharing to knowledge sharing.
We are very much familiar with what is internet ? How to use internet ? Each and every machine over Internet has unique address. The current version of Internet that we are using is known as IPv4 (Internet Protocol version 4). IP is protocol used for communication over internetwork. It is network layer protocol that provides the service of communicable unique global addressing amongst computers over Internet. An IPv4 address is a 32-bit value that's usually written in "dotted quad" representation, where each "quad" represents a byte value between 0 and 255, for example:
127.0.0.1
This allows a theoretical number of 2^32 or ~4 billion hosts to be connected on the Internet. Due to grouping, not all addresses are available today.
According to experts, the Internet as we know now will face a serious problem in coming years. Due to its rapid growth and the limitations in its design, there will be a point when no more free addresses will be available for connecting new hosts. Also during that point, no more new web servers can be set up, no more users can sign up for accounts at ISPs, and no more new machines can be set up to access the web.
One approach to solve this problem can be, by not assigning worldwide unique addresses to every user’s machine, but rather to assign them "private" addresses, and hide machines behind one official, globally unique address. This approach is called "Network Address Translation". NAT first became popular as a way to deal with the IPv4 address shortage. Hidden-Hosts behind a NAT do not have true end-to-end connectivity and cannot participate in some online Internet transaction/Communication, which is principle core of Internet. Well, various techniques were applied to solve the shortage of addressing with Ipv4, to get a better solution to this problem by having new version of protocol that fulfills future demands on address space, and also addresses other features such as privacy, encryption, and better support of mobile computing. Thus, new version of Internet Protocol is known as IPv6.
On asking Internet user to switch from IPv4 to Ipv6, there will be question why IPv6 ? Because it provides,
- Bigger Address Space
- Support for mobile devices
- Built-in Security
Bigger Address Space
IPv4 has 32-bit address, whereas IPv6 has 128-bit address location this is 4 Billion times 4 Billion times 4 Billion (2^^96) times the size of the IPv4 address space (2^^32). This works out to be:
340,282,366,920,938,463,463,374,607,431,768,211,456
This is an extremely large address space. In a theoretical sense this is approximately 665,570,793,348,866,943,898,599 addresses per square meter of the surface of the planet Earth (assuming the earth surface is 511,263,971,197,990 square meters).
Compared to the 4.4 billion addresses in IPv4, IPv6 has 3.4 × 1038 addresses, or as Wikipedia tells us,
"if the earth were made entirely out of 1 cubic millimetre grains of sand, then you could give a unique [IPv6] address to each grain in 300 million planets the size of the earth"
http://en.wikipedia.org/wiki/IP_address
Support for Mobile Device
When talking about mobile devices and IP’s, it is important to have protocol that supports mobility called Mobile IP.
If you have IPv6 going, you have support for roaming between different networks, with global notification when you leave one network and enter the other one. Support for roaming is possible with IPv4 too, but there are a number of hoops that need to be jumped in order to get things working.
Security
Security will be always on top of charts for today’s (IPv4) as well as tomorrow’s (IPv6) Internet. As a result, IPv6 protocol stacks are required to include IPsec. IPsec allows authentication, encryption, and compression of IP traffic. Except for application-level protocols like SSL or SSH, all IP traffic between two nodes can be handled without adjusting any applications. The benefit of this is that all applications on a machine can benefit from encryption and authentication, and that policies can be set on a per-host (or even per-network) basis, not per application/service.
Thus, after going through this article one must remember that it takes time for human being to get familiar, when he switches from existing thing to new thing with enhance features, similar on switching from IPv4 to IPv6, we may face problems during migrating to IPv6, Implementing IPv6 will require careful planning, a thorough review of the network’s architecture and a detailed migration plan. Training will be needed for architectural and operational personnel, and interoperability with existing IPv4 implementations will need to be maintained for quite a while.
