The problem was that transitioning to IPv6 did not offer network operators, enterprises, or vendors any clear advantages in the short term, required some expenditure, and was another protocol to manage when few IPv6 services were available.
However, the IPv4 address space is now close to depletion, it is no longer possible to easily and cheaply obtain more IPv4 addresses, and the complexity of running NATs is starting to outweigh the costs of deploying IPv6. Many ISPs and content providers also now support IPv6, and so the lack of services running on IPv6 is no longer a disincentive to deployment. IPv6 implementation is necessary and no longer something that organisations can put off until tomorrow. The L root server was added on 12 December , with G being the last on 20 October , meaning all 13 root servers are able to support IPv6 queries and responses.
The costs of transitioning to IPv6 depend on the nature of the organisation and business. All major operating systems, as well as many software applications and hardware devices are IPv6 ready, allowing organisations to deploy it as part of routine upgrade cycles. End-users should not notice when they are using IPv6 instead of IPv4, so there should be no additional training and documentation costs required for them.
However, it may be necessary to provide extra training for help desk staff who are required to troubleshoot end user systems running IPv6. IPv6 is already supported by many major network operators and content providers, and as more and more deploy IPv6, native IPv6 access will not only become the norm, but more sites will only support IPv6.
Whilst translation mechanisms exist that allow access to IPv6-only sites for those that only have IPv4, these have an impact on performance and can be difficult to troubleshoot. It is also worth considering what services and devices may need to be supported over the next few years. Your existing IPv4 address allocations may be insufficient to support a sudden increase in the number of connected devices, as many organisations experienced with the rapid deployment of IP-enabled wireless handheld products and similar devices a few years ago.
There is no specific date when everything must be upgraded to IPv6, although some organisations, including governments, have already identified target dates for their own IPv6 implementation. IPv6 and its transition mechanisms have been designed for a long period of co-existence with IPv4, and it is expected that IPv4-only systems and applications will survive for many years.
However, IPv6-only systems are expected to arise and many of these users are likely to be in emerging business markets and developing countries.
Implementing IPv6 requires planning and with the IPv4 address space nearly exhausted, network operators should already be incorporating IPv6 into their upgrade and procurement plans. In practical terms, no. This will be more than sufficient to support trillions of Internet devices for the forseeable future. Possibly never. The purpose of deploying IPv6 is to ensure network growth and continued interconnectivity when IPv4 address space becomes depleted and difficult to obtain.
In addition, as the global Internet continues to expand, it is likely that an increasing number of Internet sites will only be available via IPv6. To avoid problems, networks and connected devices should be fully IPv6-enabled to take advantage of IPv6-only sites, but IPv4 can co-exist with these until enterprises determine that it is no longer needed or cost effective to maintain. In practice, it may never be cost-effective or possible to upgrade certain legacy systems, but translation mechanisms such as NAT64 and XLAT are available to support these for as long as these are required and in use.
These port numbers are 16 bits, which means a theoretical maximum of 65, private IPv4 addresses can be associated with each public IPv4 address. Some large ISPs are even running into problems with the IPv4 address space reserved for private addresses, as the largest block This then means that multiple layers of NAT are required, which further adds to the performance and management complexity issues.
NAT can also cause problems with certain higher level protocols that were designed for end-to-end connectivity or that employ IP addresses in the application data stream, and so should really only be considered a temporary solution. IPv6 needs to be deployed to ensure the Internet continues to perform well and is able to scale into the future. Translating addresses does not provide any security benefits.
In many cases NATs require an outgoing connection to be present before they will allow an incoming connection to succeed. You should contact the RIR for your region, or alternatively your own Internet connectivity provider for more information on how to acquire IPv6 addresses.
The IPv4 address exhaustion was the major driver to develop IPv6. But by the time the IPv6 specification had matured, NAT was already used all over the internet, extending the lifetime of the IPv4 protocol.
NAT can be deployed incrementally in the internet at a low cost while also providing some basic security. On the other hand, NAT also comes with some drawbacks and will not be able to scale far enough for future needs. During the design of the IPv6 protocol, backward compatibility was not on the requirements list.
Because of this, the transition towards IPv6 does not provide a single, standardized solution to communicate with devices and systems that still run IPv4. The lack of compatibility requires operators to run IPv4 and IPv6 concurrently for the foreseeable future. This means a higher cost in maintenance now, with benefits becoming only visible when other networks are also switching to IPv6.
There is no direct benefit of being an early adopter. Nobody will switch to IPv6 as long as none of their contacts is switching too. While the adoption of IPv6 goes much slower than initially planned, the transition is already taking place. At this point, somewhere between five to six percent of traffic reaching Google is IPv6 traffic. Not much, but at least a 2 percent increase from last year.
More importantly, the transition is gaining momentum and going faster and faster each month. Google keeps statistics on the percentage of users that access Google over IPv6 , and as of today that looks like this:. But, many people just don't know. The end-user is unaware. The current operating systems are ready for IPv6 and, if available, will use it seamlessly in conjunction with IPv4. IPv6 has been slowed down for many reasons, but the transition already started and we can expect a faster and faster adoption in the years to come.
IPv6 doesn't arrive with the big drum but gets widely applied in silence all over the world. Reason 1: It's bloody expensive The internet is made up of millions of routers and switches.
Here are the latest Insider stories. More Insider Sign Out. Sign In Register. Sign Out Sign In Register. Latest Insider. Check out the latest Insider stories here. More from the IDG Network. Techniques for Prolonging the Lifespan of IPv4. Book excerpt from IPv6 for Enterprise Networks. What is IPv6 and why is it important? In addition, it also allows for hierarchical structuring of the address space in favor of optimized global routing. When a booting device in the IPv6 world comes up and asks for its network prefix, it can get one or more network prefixes from an IPv6 router on its link.
Using this prefix information, it can autoconfigure for one or more valid global IP addresses by using either its MAC identifier or a private random number to build a unique IP address. Furthermore, if we imagine the number of devices we may have in our homes that will need an IP address in the future, this feature becomes indispensable. Imagine reconfiguring your DHCP server at home when you buy a new television! Stateless Address Autoconfiguration also allows for easy connection of mobile devices, such as a smartphone, when moving to foreign networks.
The IPv6 header is much simpler than the IPv4 header and has a fixed length of 40 bytes. This allows for faster processing. It basically accommodates two times 16 bytes for the Source and Destination address and only 8 bytes for general header information. IPv4 integrates options in the base header, whereas IPv6 carries options in so-called Extension headers , which are inserted only if they are needed.
Again, this allows for faster processing of packets. The base specification describes a set of six Extension headers, including headers for routing, Quality of Service, and security. For historic reasons, organizations and government agencies in the United States used the largest part of the allocatable IPv4 address space. The rest of the world had to share what was left over. This is one explanation of why the deployment of IPv6 in Asia is much more common than in Europe and the United States.
The IPv4 address space has a theoretical limit of 4. However, early distribution methods allocated addresses inefficiently. Consequently, some organizations obtained address blocks much larger than they needed, and addresses that could be used elsewhere are now unavailable.
If it were possible to reallocate the IPv4 address space, it could be used much more effectively, but this process is not possible, and a global reallocation and renumbering is simply not practical. In addition to that it would not buy much, as even 4.
We have to take into account that in the future we will need IP addresses for billions of devices. Vendors in all industries are developing monitoring, control, and management systems based on IP.
As the previous section shows, the IPv6 working group has done more than just extend the address space. For many complex networks of today and tomorrow, and for the number of IP devices of all types, the Autoconfiguration capability of IPv6 will be a necessity. The extended address space and the restoration of the original end-to-end model of the Internet allows for the elimination of Network Address Translation NAT , in which a single or a few public IPv4 address es are used to connect a high number of users with private addresses to the Internet by mapping the internal addresses to the public address es.
NATs have become pretty common in IPv4 networks, but they create serious disadvantages in management and operation: in order to do the address mapping, NATs modify end node addresses in the IP header. There is a long list of protocols and applications that create problems when used in a NAT environment.
IPsec and peer-to-peer applications are two well-known examples. Another known issue with NAT is the overlapping of private address space when merging networks, which requires either the renumbering of one of the networks or the creation of a complex address-mapping scheme.
The amplification of limited address space, the primary benefit of NAT, is not needed with IPv6 and therefore is not supported by design. By introducing a more flexible header structure Extension headers , the protocol has been designed to be open and extensible.
In the future, new extensions can easily be defined and integrated in the protocol set. Based on the fact that IPv4 has been in use for almost 30 years, the development of IPv6 was based on the experience with IPv4 and focused on creating an extensible foundation; you can expect it to last a long time. This level of always-on connectivity with substantial bandwidth capacity means that there is greater opportunity for devices to be connected.
And many consumer electronic manufacturers have taken advantage of this. Online gaming is no longer the sole purview of games on PCs. Many telecommunication carriers are providing television-type services movies, audio content, etc. Even appliances, such as refrigerators, stoves, water heaters, and bathtubs, are getting connected. We are entering the age of smart buildings and smart cities. The end result of this network-enablement process is a greater number of devices that need addressing, many of which will not have standard user interfaces.
In these cases, the IPv6 address space, coupled with features such as Neighbor Discovery, Stateless Autoconfiguration, and Mobile IPv6, will help to usher in a new era of computerization in the home, but hopefully without the enormous deployment headache that it would cause if it were attempted with the current protocol. The growth of the wireless industry both cellular and wireless networks has been nothing short of phenomenal.
In more and more countries the number of cell phones actually exceeds the number of people. In this world of continuous reachability and reliance on the ability to access information at any time, the mobility requirements for end users have become exceptionally important. Smartphones access the Internet, play games with other users, make phone calls, and even stream video content.
We will see later that from a technical perspective, Mobile IPv6 is very elegant in its design, supporting mobile users in a highly efficient manner and providing the overlay mechanisms for users to maintain their connections when moving between networks, even if those networks do not use the same type of media access. There still remain some questions about the value of IPv6 to the enterprise, and it is worth conceding that each organization needs to evaluate the benefits and best timing of IPv6 for their own internal use.
The step-by-step introduction allows you to learn as you go, thereby saving a lot of money and headaches, and you can do it without putting the current IPv4 infrastructure at risk. With its new structure and extensions, IPv6 provides the foundation for a new generation of services. There will be devices and services on the market in the near future that cannot be developed with IPv4.
0コメント