Chapter 2: Why IPv6?

Since the introduction of TCP/IP to the ARPANET in 1973, which, at that time connected about 250 sites and 750 computers, the Internet has grown tremendously, connecting today more than 60 million users worldwide. Current estimates project the Internet as connecting hundreds of thousands of sites and tens of millions of computers. This phenomenal growth is placing an ever-growing strain on the Internet’s infrastructure and underlying technology.

It is anticipated that in the early XXI century, just around the corner, the Internet will be routinely used in ways just as unfathomable to us, today. Its usage is expected to extend to multimedia notebook computers, cellular modems, and even appliances at home, such as your TV, your toaster and coffee maker (remember that IBM’s latest desktop PC model already comes with some of these remote functionality to control your appliances at home!).

Virtually all the devices with which we interact, at home, at work, and at play, will be connected to the Internet – the possibilities are endless, and the implications staggering, especially as far as security and privacy goes.

To function within this new paradigm TCP/IP must evolve and expand its capabilities, and the first significant step in that evolution is the development of the next generation of the "Internet Protocol," Internet Protocol version 6, or IPv6.

The advent of the IPv6 initiative doesn’t mean that the technologies will exhaust the capabilities of IPv4, our Internet technology. However, as you might expect, there are still compelling reasons to begin adopting IPv6 as soon as possible. However, this process has its challenges, and as essential to any evolution of Internet technology, there are requirements for seamless compatibility with IPv4, especially with regards to a manageable migration, which would allow us to take advantage of the power of IPv6, without forcing the entire Internet to upgrade simultaneously.

Thus, IPv6 becomes a central point, the cornerstone for the Internet and its viability to serve corporate networks and the global e-commerce. This chapter elaborates on the main reasons behind the IPv6 effort, from a business and a technical perspective.

This chapter briefly:

• Discusses some of the main reasons for developing IPv6.
• Describes the main advantages and challenges in upgrading to IPv6.
• Provides a prime overview of IPv6.

The Internet Protocol

The Internet Protocol (IP) has established itself as the primary protocol for enabling a global system of electronic commerce, as well as providing means for a vast array of client/server and peer-to-peer computing applications to internetwork. Therefore, the Internet Engineering Task Force (IETF) has produced a comprehensive set of specifications, to define what it has become common known, the next-generation IP protocol, also known as "IPng," or "IPv6." One could say that the whole IPv6 effort is both a near-term and long-range concern, for both the network owners and Internet Service Providers (ISP). Even though there are already some IPv6 products on the market, the IETF is likely to keep themselves busy at least five or six years into the new century. Thus, even though IPv6 is based on much-needed enhancements to IPv4 standards, IPv6 is much new, and will provide a much-needed re-architecting and re-engineering of the almost obsolete Ipv4.

No matter the size of your organization, as long as you’re connected to the Internet, IPv6 will affect the way you do business, particularly electronically. This is true especially to ISPs and large corporations, as well as to the manufacturing industry and other large corporations. IPv6 is completely revamping Ipv4, addressing performance, scalability, security, and user friendliness when configuring it and managing networks.

To understand why so much effort has been place on a protocol, you must look at IPv6 with bi-focuses glasses, so you can see the nearsighted issues this protocol addresses as well as the farsighted one. You must look at it from the technical (nearsighted) perspective, addressing a real and to some degree urgent need, and from the business (farsighted) perspective, in light of the new e-commerce trends rapidly developing on the Internet. But be careful for not to lose sight of the farsightedness of the business needs pushing IPv6. You must look at it with glasses and not binocular or telescopes, as e-commerce and other electronic data processing trends are not that far from us!

IPv6: The Business Perspective

Some of the main reasons driving the development of IPv6

For many, IPv6 is a proposed solution for preventing IPv4’s obsolete 32-bits address space to run out of Network Layer addresses. The Internet Network Information Center (InterNIC), the authority that assigns blocks of IP addresses to large network service providers and network operators, predicts that IPv4’s address format should exhaust only around halfway into the next decade.

Some of the main changes on IPv6 from IPv4

Additional changes on IPv6 from IPv4

• Increased scaleability for network architectures,
• Improved security,
• Improved data integrity,
• Integrated quality-of-service (QoS),
• Autoconfiguration,
• Mobile computing features,
• Data multicasting, and
• More efficient network route aggregation at the global backbone level.

Some of IPv6 new features

Again, don’t be deceived by the long list of features outlined above. Just like everything has a price in this world, this many benefits of IPv6 also have a price, which can be view as a disadvantage, even though a temporary one, as it will not come without a transition effort. Such is the challenge it presents that many in the industry defend the idea of extending the life of IPv4 indefinitely with changes to the protocol standards and various proprietary techniques.

For instance, figure 2.5 outlines couple main challenges facing those migrating onto IPv6: lack of a finished product and not being PnP (Plug-and-Play). Another issue is in the case of the network address translators (NAT), which does preserves IPv4 address space by intercepting traffic and converting private intra-enterprise addresses into globally unique Internet addresses. The many quality-of-service and security enhancements to IPv4 also are being extended.

Couple main challenges for early IPv6 migrators

Nonetheless, NAT and similar extension products will never make up for the shortcomings of Ipv4. IPv4 extensions are no substitute for a protocol suite that has been designed from the ground up with scalable addressing, advanced routing, security, quality-of-service, and related features. By the same token, for high level of internal and external connectivity, which is a basic requirement for multimedia, interactive applications and transaction-oriented network applications, there is no better alternative than the features offered with IPv6.

Some professionals believe that the diversification of large applicability for IPv6 support is not something to involve and concern business and end-users in general. But you can count on the fact that IPv6 will connect more than computers and networks. IPv6 will make it possible to connect many other devices, such as palmtop personal data assistants (PDA), hybrid mobile phone embedded network components, as well as other devices and equipment that will range from a coffee maker at your kitchen to a sprinkler at a golf course.

These factors as shown on figure 2.6, justifies and contributes to some of the main challenges faced by IPv6 during its earlier implementation phase. Furthermore, as new devices make their way onto the Internet, they will strain the existing network fabric in ways the early IP protocol designers could hardly have imagined. IPv6's 128-bit address space will allow new markets to deploy an enormous array of new applications and devices for desktop, mobile, and embedded network with very high return of investment (ROI). Moreover, be confident that these new trends will be lead and pushed by end-user applications. Heavily competitively networked business environment of the new century will have to exploit all the capabilities of IPv6, not only to create a highly scalable address space, but also to take advantage of its strong capability of autoconfiguration services, capital for large networks.

Few causes responsible for the challenges presented to IPv6 during its earlier implementation.

Relevance of IPv6

Twenty years from now the Internet will be routinely used in ways just as unfathomable to us, today, as PDAs, multimedia notebook computers, cellular modems, and the World Wide Web were to those network pioneers of the 1970s and 80s. Very soon we'll be able to use our car's on-board computer to take dictation while we're stuck in traffic, update our schedule so that family and colleagues know where we are, and to instruct our house to turn up the heat, and switch on the lights. That same car will automatically run diagnostics and download the results, so when we get to the shop the needed parts are ready and waiting. Virtually all the devices with which we interact, at home, at work, and at play, will be connected to the Internet – the possibilities are endless, and the implications staggering. IPv6 will make all this possible.

Actually, IPv6 is already promoting major advantages to backbone routers, enabling efficient multitiered routing hierarchies that limit the uncontrolled growth of backbone router tables. It is also benefiting end-users, as it enables them to run more secure Intranet environments as IPv6 offers encryption and authentication services as integral part of its IP stack. The advantages are even greater for mobile users, always moving from one location to another with their notebook computers (and Palmtops). It also brings major advantages for other dynamic departmental staffs, such as team of auditors and inspectors conducting due diligence outside of their offices as IPv6 enables the use of automatic configuration in the assignment of IP addresses. The frustration of manually administration of IP addresses is over with IPv6, so it is the time-consuming and costs associated with its administration.

Although the explosive growth of the World Wide Web and other, more futuristic, technologies won't totally exhaust the capabilities of our current generation of Internet technology until early in the next decade, there are still compelling reasons to begin adopting IPv6 now. Essential to any evolution of Internet technology are the requirements for seamless compatibility with current technology (IPv4), and manageable migration. Thus, it will be possible to take advantage of the power of IPv6 now, where needed, without forcing the entire Internet to upgrade simultaneously.

There is a misconception when considering IPv6 with reference to Asynchronous Transfer Mode (ATM) cell switching, and other switching methods, as possible replacements for packet routing, that needs to be clarified. We believe ATM has its place in the internetworking industry, but cannot replace packet routing by itself. Thus, it’s not a matter of choice to have ATM or IPv6 because the two protocols not only complement each other, but also serve entirely different roles in corporate networking. As a matter of fact, why not use ATM as a transmission medium for high-speed IPv6 backbone networks? This is a question that has triggered, many standard and development work aimed on the integration of ATM and IPv6. As discussed in more details in the chapters to come, IPv6, just like IPv4, provides Network Layer services over all major link types, including ATM, Ethernet, Token Ring, ISDN, Frame Relay, and T1.

IPv6 Prime: An Overview

The Internet Engineering Steering Group (IESG) approved IPv6, or IPng, the Next-Generation Internet Protocol, on November 17, 1994 as a Proposed Standard. Since then, a large number of end-user organizations, standards groups, and network vendors have been working together on the specification and testing of early IPv6 implementations. A number of IETF workgroups have defined IPv6 projects that are well underway, including the basic IPv6 protocol specification, address architectures, Domain Name Servers (DNS), security, transition mechanisms, and Internet Control Message Protocol (ICMP). This initiative is supported by all of the major router vendors have committed to adding IPv6 to their products.

This initiative was a result of the continued exponential growth of the Internet, which exposed underlying inadequacies in the network's current technology. IPv4 was last revised in 1981 (RFC791), and for the last several years the IETF has been developing solutions for these inadequacies under the umbrella of what is called IPv6.

Enabling the convergence of all these capabilities will be "The Network", an evolution of the current Internet, but still based on the TCP/IP protocol. To function within this new paradigm TCP/IP must evolve too, and the first significant step in that evolution is the development of the next generation of the "Internet Protocol," Internet Protocol version 6, or IPv6.

Address Expansion Features

The number one issue driving the need for IPv6, but not the only one, as discussed earlier, is the rapid exhaustion of the available IPv4 network addresses. To assign a network address to every car, machine tool, furnace, television, traffic light, EKG monitor, and telephone (to name just a few), hundreds of millions of new network addresses will be needed. IPv6 is designed to address this problem globally, providing for billions of billions of addresses with its 128bit architecture.

Automatic Configuring Network Devices

Managers of major corporate networks, and Internet Service Providers are now faced with a daunting task – manually configuring and managing the vast numbers of hosts connected to their network. IPv6's Autoconfiguration capability will dramatically reduce this burden by recognizing when a new device has been connected to the network and automatically configuring it to communicate. For mobile and wireless computer users the power of IPv6 will mean much smoother operation and enhanced capabilities.

Security

The number one concerns of senior IT professionals and CEOs about connecting their organization with Intranets and to the Internet is security. The good news is that built into IPv6 are a whole host of new security features, including system to system authentication and encryption based data privacy. These capabilities will be critical to the use of the Internet for secure computing.

Real-Time Performance

One barrier to adoption of TCP/IP for real-time, and near real-time, applications has been the problem of response time and Quality of Service. By taking advantage of IPv6's packet prioritization feature TCP/IP now becomes the protocol of choice for these applications.

Multicasting

The designs of current network technologies were based on the premise of one-to-one, or one-to-all communications. This means that applications that are distributing information to a large number of users must build a separate network connection from the server to each client. IPv6 provides the opportunity to build applications that make much better use of server and network resources through its "multicasting" option. This allows an application to "broadcast" data over the network, where only those clients receive it properly authorized to do so. Multicast technology opens up a whole new range of potential applications, from efficient news and financial data distribution, to video and audio distribution, etc. The possibilities are endless!

The Conversion Challenge

While a primary design goal of IPv6 is to ease the transition from and co-existence with IPv4, converting today's tens of millions of IPv4 based systems to IPv6 will be a major challenge. However, IPv6's built in compatibility features will ease the pain, and options like tunneling IPv4 packets over IPv6, and tunneling IPv6 packets over IPv4, and translation gateways will help to make the job easier.

Many organizations are working on IPv6 drivers for the popular UNIX BSD operating environment. Network software vendors have announced a wide range of support for IPv6 in network applications and communication software products.

Changes to protocol systems can have profound effects on existing applications and must be carefully implemented to minimize risk. Thus, migrating from IPv4 to IPv6 in existing applications, or implementing IPv6 in new applications, requires considerable expertise to ensure a smooth transition and trouble-free implementation.

NOTE: For a list of articles on trade press about IPv6, please check Process Software’s (PSC) Website at http://www.process.com/ipv6/#papers. In our opinion, PSC is one of the leading in TCP/IP solutions and IPv6 tools development.

In summary, IPv6 major features, which are discussed in details in the chapters to come, are:

• Clearer spec and optimization, as IPv6 follows the practices of IPv4, and rejects the flaws and/or obsolete items of IPv4.
• Consideration to real-timeness, since IPv6 includes flowlabel mechanism in its specification, routers can recognize to which end-to-end flow the packets belongs.
• Plug and play, is included in the standard specification, which makes it easier for new users, with not much TCP/IP experience to connect their machines to the network, as all the configuration will be done automatically.
• Scalability - IPv6 has 128-bit address space, which is 4 times wider in bits in compared to IPv4's 32-bit address space.
• Security - IPv6 includes security in the basic spec. It includes encryption of packets (ESP: Encapsulated Security Payload) and authentication of the sender of packets (AH: Authentication Header).

IPv6 as a Catalyst of Business Opportunities

Vendors operating in the IP industry should be attentive for new opportunities in the IPv6 market, as we already anticipate market dynamics, which will lead to universal IPv6 adoption, as discussed earlier in this chapter. In order to be successful, vendors should be looking for product concepts, which leverage these market dynamics.

One market to tap on is the fact that IPv6 stack is incompatible with IPv4 stack. The IETF is formalizing two approaches to the migration process: tunneling and dual stacks, which are discussed later in this book.

Tunneling, as shown on figure 2.7, is an alternative, as it addresses the incompatibility of the infrastructure – by enabling two IPv6 nodes to communicate over an IPv4 backbone (or vice versa), but it does not enable an IPv4 node to communicate with an IPv6 node. But what if a node with a dual IPv6/v4 stack, which could communicate with either IPv6 or IPv4 nodes were available? Would dual stacks resolve the migration issues?

The transmission of IPv6 packets can be made of IPv4 via tunneling

If so, would you install a dual stack instead of IPv4 only? Clearly this would require a considerable investment, especially at a large site, and coordination of stacks from different vendors would be necessary. Also, upper level protocols would need to be replaced, and a "separate but equal" addressing and configuration scheme would need to be implemented and supported. The question is why would you incur in these costs and risks? The possible answers could be:

1. You may want to have some target nodes only accessible via IPv6. But why would you do that when such a choice so severely constrains communicating nodes in your organization?
2. Surely, many are the compelling features of IPv6. You may decide to endure the challenges brought by IPv6 just like any Microsoft users endures the beta versions of Windows 98 and NT 5.0: you may do it for the attributes of IPv6, such as quality-of-service, automatic configuration, security and large address space. All to be also available via IPv4 or have adequate IPv4 workarounds for the next decade.

This is an IPv6 constraint. I’m not sure that the advantages of dual stack installation warrant the costs and risks,. It does, however, poses a "chicken or egg" conundrum for early IPv6 adopters.

But there is an alternative approach that may mitigate this problem. What about a device (or scheme) that translates between IPv4 and IPv6 protocols, as shown on figure 2.8? IPv4 nodes, which need to communicate with IPv6 nodes, would not require any stack upgrades. New sites might consider IPv6 installations without fear of incompatibility with the installed base. IPv6 migration could proceed based on its larger address space.

Using a translation scheme to bridge IPv6 and IPv4 packets.

By the time you reading this, the alternative will be no longer new. This proposition is not only very similar to that of Network Address Translation (NAT) devices, as NAT boxes may be used to translate between one IPv4 address space and another disjoint IPv4 space, but there are few initiatives at works. One of the most prominent one is 6bone, which is discussed next.

6Bone: A Brief Overview

The 6bone outgrow independently from the IETF IPng project and is currently an informal collaborative project covering North America, Europe, and Japan. Since we can’t place IPv4 routers at risk until IPv6 is fully tested and implemented, 6Bone proposes a way to provide Internet-wide IPv6 transport in an organized and orderly way for early testing and use.

An automatically drawn from the 6bone Registry tunnels for the sites shown.

As you might expect, as confidence builds to allow production routers to carry native IPv6 packets, 6bone will tend to disappear as it will be progressively replaced by a more transparent transport interface of ISP and user network IPv6 Internet-wide.

The 6bone can then be seen as a migration tool, designed to easy on the transition to IPv6 in a reasonable fashion so testing and experience can be carried out. As more ISP and user network operators are involved in the 6bone process better knowledge of the process and seamless transition to IPv6 can be achieved.

NOTE: The 6bone activity is now in the process of becoming an IETF Working Group under the Operations Area. The current draft of the 6bone WG Charter with goals and milestones can be found at the URL http://www.6bone.net/

From Here

This chapter provided an overview of the rationale for the development and need of upgrading to IPv6. It discussed some of the advantages of IPv6 as well as the challenges it faces. The next chapter, "IPv4 Limitations and Constraints," will deepen the discussion about IPv4 limitations and challenges, such as IPv4’s addressing system and management, and the enhancements of IPv6 in this area.