Presented by:Jubin Jose
The Adoption Of IPv6
There is no question the Internet has revolutionalized the world. Many of the things we take for granted today were not even possible a few years ago. Will the Internet continue to push the boundaries of technology? The answer lies within IPv6. IPv6 will replace IPv4 as the standard addressing scheme of the Internet. Why do we need a new addressing scheme? There are numerous amounts of limitations in IPv4, namely, the shortage of addresses. Most countries, excluding the United States, do not have nearly as many IP addresses as they need. The United States owns 70 of the available IP addresses, so it is no surprise that the United States is not pushing for a quick transition to the new technology. This is all new material for professional technologists. The first implementation was IPv4, which built the addressing scheme, but now IPv6 is the first step to revise and expand it. This will take extraneous time and perseverance to complete the Internet Protocol next generation. The European Union and Japan are leading the transition to IPv6. This is inevitable since they rely on the Internet as much as the Americans, yet own significantly fewer IP addresses. IT professionals question the theory of which to upgrade first the Domain Name Server (DNS), routers, or hosts. There is not an IPv6 DNS root server. Presently, the DNS implementations all run on top of IPv4 addresses and the DNS system that supports IPv6 is linked to IPv4 information. Some DNS implementations are beginning to support national IPv6 transitions, such as, bind8 with a KAME patch, or newbie and bind9 (which are still under development). Upgrading these servers is a crucial step in the conversion process. Asia is in the process of implementing 6Bone, a virtual network layer that allows IPv4 and IPv6 to coexist. This is a major requirement for a smooth transition to IPv6. Without an intermediate layer like 6Bone, the only alternative would be to change every network in the world over to IPv6 on a specified day at a specific time-not a very ideal situation. Japan's 6Bone will take 4-5 years to complete, not including additional time to debug and fix errors.
1.1 Need for a New Version of IP
IP version 6 is a new IP protocol designed to replace IP version 4, the Internet protocol that is predominantly deployed and extensively used throughout the world. The current version of IP has not been substantially changed since RFC 791, Internet Protocol DARPA Internet Program Protocol Specification was published in 1981. IPv4 has proven to be robust, easily implemented, and interoperable, and has stood the test of scaling an internetwork to a global utility the size of the Internet today. However, the initial design did not anticipate the following conditions:
• Recent exponential growth of the Internet and the impending exhaustion of the IPv4 address space
• Growth of the Internet and the ability of Internet backbone routers to maintain large routing tables
• Need for simpler autoconfiguration and renumbering
• Requirement for security at the IP level
• Need for better support for real-time delivery of dataalso called quality of service (QoS)
Note: Features such as IP Security (IPSec) and QoS have been specified for both ver-sions of IP. Though the 32-bit address space of IPv4 supports about 4 billion IP devices, the IPv4 addressing scheme is not optimal, as described by Christian Huitema in RFC 3194, The Host-Density Ratio for Address Assignment Efficiency: An Update on the H Ratio. A good number of the initially allocated class A addresses are probably still not used, but are not likely to be reclaimed. The Internet Engineering Task Force (IETF) first recognized the problem of eventual IPv4 address exhaustion around 1990 and predicted that we had about ten years to solve this problem. Interestingly, this prediction was made before the explosive growth of the Internet and the World Wide Web in the 1990s. Indeed, it is only very recently that the IP address has become widely acknowledged. The current IP address space is unable to satisfy the potential huge increase in the number of users or the geographical needs of the Internet expansion, let alone the requirements of emerging applications such as Internetenabled personal digital assistants (PDAs), home area net¬works (HANs), Internet-connected transportations (for example, automobiles), integrated IP telephony services, IP wireless services, and distributed gaming.
IPv6 is designed to meet these requirements and allow a return to a global environment where the addressing rules of the network are again transparent to the applications. The lifetime of IPv4 has been extended using techniques such as address reuse with Net¬work Address Translation (NAT), classless interdomain routing (CIDR), and temporary-use allocations (Dynamic Host Configuration Protocol [DHCP] and RADIUS/PPP). Al¬though these techniques appear to increase the address space and satisfy the traditional server/client setup, they fail to meet the requirements of the peer-to-peer and server (home)-toclient (Internet) applications. The need for always-on environments (such as residential Internet through broadband, cable modem, or Ethernet-to-the-home) to be contactable precludes these IP address conversion, pooling, and temporary allocation tech-niques, and the plug-and-play required by consumer Internet appliances further increases the address requirements. Temporary or semipermanent connections such as dialup or cable modem/xDSL are being given either temporary IPv4 addresses or private addresses. Millions of the new technology devices such as wireless phones, PDAs, cars, and home appliances will not be able to get global IPv4 addresses any longer. Though we do not expect to ever see the last IPv4 address handed out, it is getting much harder to get IPv4 addresses.
1.2 Network Address Translation
Emerging countries are facing the IPv4 address crunch more strongly than Europe or the United States. Although the use of NAT has delayed the IPv4 address exhaustion, the use of NAT introduces some complications that can be overcome only with a new IP protocol. In IPv4 networks, NAT is typically used to connect internal networks by translating packets between an internal network, which uses the private address space, as described in RFC 1918 Address Allocation for Private Internets, and the Internet. NAT uses only a few global (external) addresses even in a large internal network. Limitations of NAT Note that the use of NAT only delays the time of exhaustion of the IPv4 addresses but does not solve the real large-scale growth problem, because IP is now widely adopted as the application's convergence layer for noncomputing devices. Additionally, use of NAT has many implications, as identified in RFC 2775, Internet Transparency, and RFC 2993, Architectural Implications of NAT. Some of these problems follow and can be solved only with a new protocol, such as IPv6: With IPv4, only the endpoints handle the connection and the underlying layers do not handle any connection. However, when NAT is used, it breaks the end-to-end connection model of IP. Because NAT must handle the translation of addresses and ports, NAT requires the network to keep the states of the connections. In case of failure of the NAT device or the links near the NAT device, the need to keep the state of the connections in NAT makes fast rerouting difficult. NAT also inhibits the implementation of end-to-end network security. The integrity of the IP header is protected by some cryptographic functions. This header cannot be changed between the origin of the packet, which protects the integrity of the header and the final destination, where the integrity of the received packet is checked. Any translation of parts of the headers along the path will break the integrity check With applications that are not "NAT-friendly," more than just port and address mapping is necessary to forward the packet through the NAT device. NAT must embed complete information of all the applications to accomplish this goal, especially in the case of dynamically allocated ports with rendezvous ports, embedded IP addresses in application protocols, security associations, and so on. Every new deployment of a non-NAT-friendly application will require the upgrading of the NAT device. When different networks that are using the same private address space, such as 10.0.0.0/8, need to be combined or connected, as in the case of a merger, an address space collision will result. Though techniques such as renumbering or twice-NAT can resolve this collision, these techniques are very difficult and will increase the complications of NAT. The ratio of internal/reachable to external addresses mapping must be large to make NAT effective. However, when there are many servers inside, the same protocol cannot be multiplexed on the same port using the NAT external address. For example, two internal servers using the same port (80) cannot use the same external outside address without changing the port number. Each inside server that must be reachable from the outside will start using one external address. Because there are many protocols that make nodes as servers and consume many external addresses, NAT is not quite as useful if the number of inside servers is large.
1.3 Meeting future requirement
Though the exhaustion of IPv4 addresses is the primary reason for the development of a new protocol, the designers of IPv6 added other new features and some critical im-provements to IPv4. IPv6 is designed to meet the user, application, and service require-ments, and allow a return to a simpler environment where the operation of the network is again transparent to the applications. The anticipated rollout of wireless data services has been identified as a key IPv6 driver. The wireless industry standardization bodies, for example, the 3rd Generation Partnership Project (http://www.3gpp.org), Universal Mobile Telecommunication System (http://www.umts-forum.org), and Mobile Wireless Internet Forum (http://www.mwif.org) are considering IPv6 as the foundation for future IP services. Today, IPv6 services are available over IEEE 802.11 from some hot-spot locations. The overall market adoption of IPv6 will be determined by the ability of the architecture to best accommo¬date Internet growth, new IP applications, and services. All these factors underscore the original rationale behind definition of IPv6 and the market drivers. Evolution of Internet Protocol Version 6 IPv5 is an experimental resource reservation protocol intended to pro-vide QoS, defined as the Internet Stream Protocol or ST. ST is not a replacement of IP, but uses an IP version number (number five), because it uses the same link-layer framing as IPv4. Resource reservation is now done using other protocols (for example, resource reservation protocol (RSVP)). IPv5/ST protocol is documented in RFC 1190, Experimen¬tal Internet Stream Protocol, Version 2 (ST-II) and RFC 1819, Internet Stream Protocol Version 2 (ST2) Protocol Specification - Version ST2+. The original proposal for IPv6 proposed in RFC 1752, The Recommendation for the IP Next Generation Protocol was the Simple Internet Protocol Plus (SIPP) with a larger (128 bit) address space. The main author of SIPP was Steve Deering, now a Cisco Fellow. Following that proposal, the IETF started a working group and the first specification came in late 1995 with RFC 1883, In¬ternet Protocol, Version 6 (IPv6) Specification. RFC 2460, Internet Protocol, Version 6 (IPv6) Specification, by Steve Deering (Cisco) and Rob Hinden (Nokia), obsoletes RFC 1883 and is the present standard for IPv6. IPv6 quadruples the number of network ad¬dress bits from 32 bits (in IPv4) to 128 bits, which provides more than enough globally unique IP addresses for every network device on the planet. The use of globally unique
IPv6 addresses simplifies the mechanisms used for reachability and end-to-end security for network devices, functionality that is crucial to the applications and services that are driving the demand for the addresses. The flexibility of the IPv6 address space provides the support for private addresses but should reduce the use ofNetwork Address Transla-tion (NAT) because global addresses are widely available. IPv6 reintroduces end-to-end security and quality of service (QoS) that are not always readily available throughout a NAT-based network.
1.4 Works on the Topic
Extensive research, design, and organization has been put forth by the European Union (EU) and Japan in the quest to implement Internet Protocol version 6 (IPv6). Both efforts will be collaborated into finalizing the new generation of Internet protocol. The European Commission's IPv6 task force and the IPv6 promotion council of Japan said in a joint statement that they will cooperate "to foster promotion and deployment and garner support for the new generation Internet Protocol. The European Union is completing its second phase, contracting international cooperation agreements to help set up IPv6 task forces at national and regional levels. They recommended deployment strategy by network designers is to begin at the edge and then move towards the network core reducing costs and operational impacts of integration. Next is the deployment of IPv6 throughout Europe by a 2005 due date. With Japan's construction of 6Bone and other useful software to implement the change this should not be a challenge. We all know the benefits from the new protocol. We do not know the problems it has in store. A major concern is the ongoing Questions "What securities will it provide?" or "Will it cause more intense types of failures?" Truth is no one knows. IPv6 is being implemented and there is no telling what to expect. Experts are embarking upon new and untainted ground. They are just starting the foundation and as the past has shown there are many complications waiting to be discovered as well. And where is the United States in all of this commotion? Since the US still has quite a few Internet protocol address left there isn't a demand for the implementation of more. However, the US does have its hand in developing IPv6; in fact Microsoft is one of the leading designers for the switch. Microsoft, Cisco, and others have a few of its top computer experts overseas assisting international efforts for developing the future's technology. In some perspective, the US is waiting to see what problems will occur from the new protocol and research its effects. Then when all of the flaws are squared away the US will play and intense game of catching up, but this is only a theory. Another decision which has caused numerous headaches is what to implement first. The domain name servers (DNS) deal with the most transport of data so they were chosen first to upgrade. The IPv4 address scheme will be compacted into the IPv6 address. With the IPv6 addressing scheme there is an excess of room to be filled. There is an added section of the IPv6 address to deal with telling the server what type of protocol to handle. This allows the servers to communicate with dual IPv4/IPv6 encoding of the data. This process changes data from IPv4 by adding zeroes in the address or just by putting zeros in the empty spaces. The server will pick up these zeros or emptied space colons (which are used to shorten a lengthy amount of zeros) and read the address as an IPv6. Then normal computations will take place. With the next generation of protocol intact, the possibilities are endless to what computers can accomplish.