Apr 30, 2008
Goscomb Technologies today announces the availability of its 24Mbps broadband services to the general public
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IPv6
Network Support
Contents
A Brief History of...
In 1991, the IETF decided that the current version of IP, called IPv4, had outlived its design. The new version of IP, called either IPng (Next Generation) or IPv6 (version 6), was the result of a long and tumultuous process which came to a head in 1994, when the IETF gave a clear direction for IPv6.
What is IPv6?
IPv6 is designed to solve the problems of IPv4.
It does so by creating a new version of the protocol which serves the function of IPv4, but without the same limitations of IPv4.
IPv6 is not totally different from IPv4: what you have learned in IPv4 will be valuable when you deploy IPv6.
The differences between IPv6 and IPv4 are in five major areas: addressing and routing, security, network address translation,
administrative workload, and support for mobile devices. IPv6 also includes an important feature: a set of possible migration and transition plans from IPv4.
We talk about these differences in more detail, below.
Since 1994, over 30 IPv6 RFCs have been published.
Changing IP means changing dozens of Internet protocols and conventions, ranging from how IP addresses are stored in DNS (domain name system) and applications,
to how datagrams are sent and routed over Ethernet, PPP, Token Ring, FDDI, and every other medium, to how programmers call network functions.
The IETF, though, is not so insane as to assume that everyone is going to change everything overnight.
So there are also standards and protocols and procedures for the coexistence of IPv4 and IPv6: tunneling IPv6 in IPv4,
tunneling IPv4 in IPv6, running IPv4 and IPv6 on the same system (dual stack) for an extended period of time,
and mixing and matching the two protocols in a variety of environments.
Why use IPv6?
Most of today's internet uses IPv4, which is now nearly twenty years old. IPv4 has been remarkably resilient in spite of its age, but it is beginning to have problems.
Most importantly, there is a growing shortage of IPv4 addresses, which are needed by all new machines added to the Internet.
IPv6 fixes a number of problems in IPv4, such as the limited number of available IPv4 addresses.
It also adds many improvements to IPv4 in areas such as routing and network autoconfiguration.
IPv6 is expected to gradually replace IPv4, with the two coexisting for a number of years during a transition period.
IPv6 Features
The main improvement brought by IPv6 is the increase in the number of addresses available for networked devices, allowing, for example,
each mobile phone and mobile electronic device to have its own address.
IPv4 supports 232 (about 4.3 billion) addresses, which is inadequate for giving even one address to every living person,
let alone supporting embedded and portable devices.
IPv6, however, supports 2128 (about 340 billion billion billion billion) addresses,
or approximately 5×1028 addresses for each of the roughly 6.5 billion people alive today. With such a large address space available,
IPv6 nodes can have as many universally scoped addresses as they need, and network address translation is not required.
Address Space
- Increase from 32-bit to 128-bit address space;Management
- Stateless autoconfiguration means no more need to configure IP addresses for end systems, even via DHCP;Performance
- Predictable header sizes and 64-bit header alignment mean better performance from routers and bridges/switches;Multicast/Multimedia
- Built-in features for multicast groups, management, and new "anycast" groups;Mobile IP
- Eliminate triangular routing and simplify deployment of mobile IP-based systems;Virtual Private Networks
- Built-in support for ESP/AH encrypted/authenticated virtual private network protocols; built-in support for QoS tagging.
Migration
IPv6 is a natural increment to IPv4. It can be installed as a normal software upgrade in internet devices and is interoperable with the current IPv4. Its deployment strategy was designed to not have any "flag" days. IPv6 is designed to run well on high performance networks (e.g., ATM) and at the same time is still efficient for low bandwidth networks (e.g., wireless). In addition, it provides a platform for new internet functionality that will be required in the near future.