Introduction to Internet Protocol - Version 6

Introduction to Internet
Protocol - Version 6
WHITE PAPAER
Author: Sandeep Lugani
Internet Protocol Version 4 (IPv4)is the most popular protocol in use today, although there are some
questions about its capability to serve the Internet community for much longer. IPv4 was finished in
the 1970s and has started to show its age. The main issue surrounding IPv6 is in addressing—or, the
lack of addressing—because many experts believe that we have nearly run out of the four billion
addresses available in IPv4. Although this seems like a very large number of addresses, multiple
large blocks are given to government agencies and large organizations.
IPv6 could be offer the solution to the many problems being faced by IPv4, but it is still not fully
developed and is not a standard—yet. The next generation Internet Protocol (IPv6) is poised to make
a new wave in the coming decade. If you wonder what the big deal is about, you need to look at some
serious limitations of the current IP protocol, or IPv4 to be precise.
Limitation of Internet Protocol - Version 4
Address Space
When the TCP/IP protocol was initially designed, the proponents had not the faintest idea that the
Internet will one day propel the World Wide Web and support the great conflagration of people and
devices hooked into it. The current protocol, from this perspective, has many shortcomings and flaws.
One of them is the address space problem. As many of us are aware, the current 32-bit addressing
used within IP is not allocated well, resulting in huge gaps of unused addresses. Also, the Internet is
expanding at an exponential rate, with many more devices getting added to the network every day.
Do we have a wide enough address space for them?
Security
Another glaring issue is the lack of security and authentication. IP does not encrypt packets. You
cannot digitally sign a transmission. It is relatively easy to monitor TCP connections, even hijack them
and make them yours. Hackers all over the world routinely use such tools to break into systems.
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Most protocols that require passwords over IP connections use clear text passwords. Why not
encrypt such passwords? There are many additional add on software that can be used to surmount
some of these problems, but the problem itself originates with the protocol that belongs in the middle
ages - when compared with today's needs and standards.
QOS
If you stream an audio or video over the Web, there is no guarantee that you will have enough
network bandwidth consistently to deliver the goods. In addition, the Internet today doesn't have a
structure that reflects IP address allocation, thus requiring huge routing tables to be maintained by
routers. Network congestion abounds. Can it deliver the goods as technology races on? Thus is the
status with IP version 4 (IPv4) that is in use today.
Internet Protocol - Version 6
IP version 6 or IPv6 is also known as IPng - (ng for new/next generation). The changes from IPv4 to
IPv6 fall under the major categories described below.
Expanded Addressing Capabilities
IPv6 increas es the IP address size from 32 bits to 128 bits, to support more levels of addressing
hierarchy, a much greater number of addressable nodes, and simpler auto-configuration of
addresses. The scalability of multicast routing is improved by adding a "scope" field to multicast
addresses. A new type of address called an "anycast address" is defined, and can used to send a
packet to any one of a group of nodes.
Header Format Simplification
Some IPv4 header fields have been dropped or made optional, to reduce the common-case
processing cost of packet handling and to limit the bandwidth cost of the IPv6 header.
Improved Support for Extensions and Options
Changes in the way IP header options are encoded allows for more efficient forwarding, less
stringent limits on the length of options, and greater flexibility for introducing new options in the future.
Flow Labeling Capability
A new capability is added to enable the labeling of packets belonging to particular traffic "flows" for
which the sender requests special handling, such as non-default quality of service or "real-time"
service.
Authentication and Privacy Capabilities
Extensions to support authentication, data integrity, and (optional) data confidentiality are specified for
IPv6
Description of Internet Protocol - Version 6 Packet Header
The format consists of Version, Class, Flow Label, Payload Length, Next Header, Hop Limit, Source
Address, Destination Address, Data, and Payload fields.
4 bits
version
16 bits
Payload Length
8 bits
Traffic Class
128 bits
Source Address
126 bits
Destination Address
8 bits
Next Header
24 bit
Flow Label
8 bits
Hop Limit
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Address Description
Expanded addressing moves us from 32-bit address to a 128-bit addressing method. It also provides
newer unicast and broadcasting methods, injects hexadecimal into the IP address, and moves from
using "." to using ":" as delimiters
An IPv6 address is represented as 8 16-bit numbers in hexadecimal, like
FEDC:BA98:0:0:0:BA98:7654:3210. It is not possible to remember these. And you don't have to. The
DNS service will be modified to handle both 32-bit and 128-bit addresses. Also, an IPv6 address can
be dynamically built when you plug in a device, by sensing the network address from the network you
are connecting to, and then using your ethernet card's address (or the hardware address of whatever
interface you are using) to build an IPv6 address. Thus you can reconfigure automatically when
moving from place to place. Your IPv6 addresses also change.
Routing with Internet Protocol - Versi on 6
Routing has been totally reworked to build hierarchies. That is, the IPv6 address itself tells the
network where exactly to deliver the packets. These addresses will be portioned out to various ISPs
and regulatory bodies and a huge chunk kept in reserve. This also means that your IPv6 address will
change when you move to another ISP (this is currently effective due to CIDR - classless InterDomain
routing - which was invented to temporarily surmount the huge problems with addressing and routing
tables).
Anycast
Broadcasting is done away with in IPv6. Only multi-casting is present. There is also an "anycast"
feature where multiple devices listen on the same address, but the packet will be sent to only one, the
"nearest" device. Currently this definition can be used only by routers. This would allow, for example,
the Microsoft Network worldwide to use the same IPv6 address for ALL its routers. Your packet will go
to the NEAREST router depending on which part of the world you are currently located in. Combined
with plug-and-play, this is ideal for mobile devices.
Jumbograms
IPv6 datagrams can be Jumbograms (upto 4 billion bytes long)!. This is for better resource utilization
in very fast networks (possibly intranets). You can "tunnel" IPv6 packets through IPv4 networks using
machines that have "dual stacks" (running both IPv6 & IPv4) at the edge of the network. You can also
tunnel IPv4 packets through an IPv6 network by using special addressing schemes on the IPv6
network edges. However, to make full use of IPv6 features - including security and quality-of-service
(QoS) - currently running applications will have to be modified. The socket APIs will expand, and
many of the higher level abstractions can change to accommodate IPv6 features and addressing.
QOS
Quality of service (QOS) is a very important feature of IPv6. In fact, this is what has made ATM
networks popular. IPv6 makes it possible to make network bandwidth reservations on traffic flows. A
protocol known as RSVP (Resource Reservation Protocol) is invoked here. Essentially, all routers in
the path recognize and honor flow-reservations and expedite or slow down packets as required, to
meet bandwidth guarantees. They can also timeout and free up resources that are unused. RSVP
can be applied to multicast as well! The end result is that multimedia streaming applications may
reserve network bandwidth and proceed without worrying about delivery hassles.
Obstacles to Internet Protocol - Version 6 Deployment
There are a number of obstacles to widespread deployment of IPv6. Primary among them is the
comfort level with existing solutions and the pain of changing networks that currently work (even
though they contain many "workarounds" to overcome IPv4's limitations). The obstacles for IPV6 are
based on technological as well as business reasons. If the migration is seen as a wave that must
include end users, vendors and service providers, it becomes clear that each group has its own set of
reasons to hesitate before embracing IPv6.
US vs. the Rest of the World
The 20 th century has been characterized by US leadership in technology. The ongoing recession in
US and Sept, 11 disaster has hit the economy and prevented Network Managers from new
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investments in Technology. Several trends, including the PC wave, started in the US and then
spread throughout the world. The situation is likely to be quite different when it comes to IPv6
because US companies have done quite well when it comes to their allocation of IPv4 addresses
compared to the rest of the world. While European and Asian companies are motivated to migrate
because of a shortage of IP addresses. Major US companies often still have blocks of addresses they
have never used. It should be pointed out that smaller US companies that grow rapidly are faced with
the problem of insufficient addresses, but they often find workarounds for this problem.
No "Killer Application" for Internet Protocol - Version 6
Most technology upgrades are driven by a "killer application." Unless increased address space itself is
viewed as a "killer application," many opponents of IPv6 argue that there is no compelling reason to
migrate. This by itself, is not so enticing and becomes a non-argument when migration is proposed.
Few Existing Compliant Products
While there have been some early products, such as Sendmail, that support IPv6, there has not been
an explosion in IPv6 products. Only Microsoft has begin shipping IPv6-compliant products, there will
not be awareness in the market for IPV6 that their products have to support this new protocol.
Cost Is a Factor
For any new technology migration, cost always play a crucial role. The world will not necessarily
decide one day to migrate en masse to IPv6 - the problem of supporting two protocols means
additional expense as well as network overhead for companies. Whether that means supporting dual
protocol stacks, gateways or encapsulation of packets, there will be significant cost for large
enterprises to migrate to IPv6.
Network Address Translation (NAT)
Majority of the companies simply advertises one address to the outside world and then translates that
address into the appropriate address internally. NAT provides greater security since the real
addresses of internal sites are hidden behind the real IPV4 address. Due to this reason, companies
have opted to use private addressing internally and not even worry about possible duplication of IP
addresses with external users since those addresses are never routed outside and are never seen
outside the firewall.
Opportunities in India/APAC
Market trend and Growth Scenerio
Itappears that the original timetable for IPv6 adoption has been set back by at least 18 months. It will
be at least the third quarter of 2006 before IPv6 nodes surpass IPv4 nodes
The wireless industry can be the strongest driving force for the rapid migration from IPv4 to IPv6
because of the number of IP addresses needed for Internet access from third-generation cell phones.
This trend seemed inevitable last year when the Third Generation Partnership Program (3GPP), a
European wireless organization, adopted IPv6 as its standard.
For the past several months, service providers have cut back on their expenditures as evidenced in
revenue declines for vendors such as Cisco and Nortel. There is very little pressure on service
providers to add IPv6 because many enterprises have postponed IT projects until the economy
improves.
The significant lack of interest in IPv6 in the United States implies that growth will take place first in
parts of the world where IP addresses are in short supply. There are signs that the Asia-Pacific will
be a leader in the migration to IPv6. Japan currently has a serious lack of IPv6 addresses so it
should come as no surprise that the Japanese government has set a deadline of 2005 for the
adoption of IPv6. NTT DoCoMo has plans to roll out third-generation wireless services later this year.
There is also significant IPv6 activity in Hong Kong, China and Australia. Europe will follow, but its
migration will be predicated on how quickly the wireless industry turns healthy. Wireless Internet
access remains the key driver that could force European providers to offer IPv6 services.
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INTERNET PROTOCOL - VERSION 6 Growth Statistics
It is positioned by independent agencies that the number of installed IPv6 nodes will not surpass the
number of installed IPv4 nodes until the third quarter of 2006. Should economic conditions not
rebound until 2002, the wireless industry will have little chance of launching successful thirdgeneration
wireless services. The lack of a large installed base of European wireless Internet users
will mean a limited need for more IP addresses and a roadblock to IPv6’s chances of overtaking IPv4.
Under such conditions, IPv6 would not attain majority status until 2007.
Vendors
Cisco has already announced that it will support IPv6 beginning with its IOS release 12.2(1)T and that
the IPv6 support will also be available as a free download to customers with maintenance contracts.
The vendor is adding IPv6 support later this year for its carrier-class 7600 and 12000 routers and its
Catalyst 6000 enterprise switches. Microsoft has reiterated recently that it will support IPv6 in its
Windows XP
Summary
Over the next 10-15 years, the Internet & the Web would probably evolve beyond our imagination.
IPv6 tries to forecast that picture and ensure that many of the possible requirements of the future are
addressed. It also has to maintain inter-operability with legacy networks like those using Novell IPX.
Think of this as something like a transition from an Intel 8088 chip to a Pentium IV, maintaining
compatibility, but vastly enhancing the scope.
Performance-wise, IPv6 is expected to give a real boost compared to IPv4, due to efficient routing,
good packet structure, Quality-of-service. The transition stage requires that most routers upgrade
over a short time to new and faster technology, and of course any future technological innovations
expected on the Internet.
About Wipro Infotech
Wipro Infotech, a division of Wipro Limited (NYSE:WIT), provides enterprise customers with
high value Information Technology Products, Services and Solutions in India, and provides
Technology & Software Services in the Asia Pacific and the Middle East. Wipro Infotech's
position of leadership in this business is built on a strong foundation of Quality processes,
including Six Sigma, ISO, Knowledge Management & People processes (PCMM- People
Capability Maturity Matrix). Headquartered at Bangalore, India, Wipro Infotech has business
offices in Dubai, Saudi Arabia, Singapore, Sydney, Taipei & Hong Kong in the Asia Pacific &
the Middle East.
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