Next generation IP addressing IPv6

Internet protocol IPv6 is the latest IP protocol which also works on layer 3 aka network layer of OSI model. IPv6 fulfills the current deficiency of IPv4 addresses. It is implemented mostly in Asian countries such as Japan and China. Many corporate organizations are working on migrating themselves from IPv4 to IPv6 setup in order to fulfill their current corporate needs.

A little bit History:
Let us see a little bit history of the evolution of this powerful IP addressing scheme.

Vocabulary words:
1) Proliferation : increase in numbers.
2) Anticipated : expected.

In late 1980s even after the redesign of the addressing system using a classless network model, It became clear that this would not suffice to prevent IPv4 (predecessor of IPv6 protocol) address exhaustion and that further changes to the internet infrastructure were needed.

Some Facts:

•  In 1992′s end the creation of the working groups on IP next generation (IPNG) area.
•  IETF (Internet engineering Task Force) adopted the IPNG model on July 25, 1994, with the formation of several IPNG – working groups.
•  By 1996, a series of RFCs (Request For Comments) were released defining IPv6 .
•  IPv5 was used for the experimental basis by Internet Stream Protocol.

It was widely expected that IPv4 will be supported alongside IPv6 for the foreseeable future. IPv4-only and IPv6-only nodes can not communicate directly and need assistance from mechanisms such as tunneling.

IPv4 Exhaustion:

•  Estimates of the time of the complete IPv4 exhaustion varied widely in the early 2000’s. But by 2009 all converged  on the time frame from 2011 to 2012.
•  In 2003, the director of Asia Pacific Network Information Centre (APNIC) is the Regional Internet Registry for the – Asia Pacific region, “Paul Wilson” stated that “based on then current rates of deployment, the available space would last for one or two decades.”
•  In September 2005, a report by Cisco Systems suggested that ” The pool of available addresses would exhaust in as – little as four to five years. ”
•  In 2008, a policy process started for the end-game and post-exhaustion Era.
•  In 2010, a daily updated report projected the global address exhaustion pool for the first quarter of 2011, and depletion of the five regional internet registries before the end of year 2011.
•  At the end of January 2011, the Internet Assigned Numbers Authority (IANA) assigned the last - two allocation blocks according to its request procedures, leaving only five blocks unused, per policy, each of the - five regional registries receives one of the remaining blocks, effectively depleting the global pool.
•  It is expected on February 3rd,2011, that there will be a formal announcement in the US that IPv4 addresses have been completely exhausted.

IPv4 comparison with IPv6:


Now lets talk about some comparisons between IPv4 and IPv6. Following is the picture of comparison of IPv4 and IPv6 headers.

Comparison of IPv4 vs IPv6 Headers.

IPv6 specifies a new "Packet format" , designed to minimize packet headers processing by routers.

Uninteroperability:


Because the headers of IPv4 packets and IPv6 packets are significantly different, the two protocols are not "INTEROPERABLE". However, in most regards, IPv6 is a conservative extension of IPv4. Most transport and application layer protocols need little or no change to operate over IPv6; [exceptions are application protocols that embed internet-layer addresses, such as FTP and NTPv3].

1) Larger address space of IPv6: The most important feature of IPv6 is a much larger address space than in IPv4. The size of IPv6 address is 128 bits compared to 32 bits in IPv4. The address space is therefore supports 2 ¹²⁸ or approximately 3.4 x 10 ³⁸ addresses. By comparison, this amounts to approximately 5 x 10 ²⁸ addresses for each of the 6.8 billion people alive in 2011.

While IPv4 has only 2 ³² addresses which is very small as compare to IPv6 and in order to make the best use of the address space complex Classless Inter-Domain Routing (CIDR) methods were developed.

2) Standard size of a subnet of IPv6:

The standard size of a subnet of IPv6 is 2 ⁶⁴ addresses which is the square of the size of the entire IPv4 address space. Thus, actual address space utilization rates will be small in IPv6. Also network management and routing efficiency is improved by the large subnet space and hierarchical route aggregation.