02-03-2011 10:51 AM - edited 03-01-2019 04:37 PM
In February 2011, the last of the large unused IPv4 addresses blocks have been allocated but the Internet continues to grow despite the imminent exhaustion of address space. In order for growth to continue uninterrupted, the Internet and all of its users will have to make a transition to IPv6, a protocol which provides a practically unlimited number of endpoint addresses. IPv6 has already been deployed in many large Cisco networks, but the depletion of IPv4 addresses has served to inspire greater IPv6 adoption; a number of organizations are outlining ambitious transition plans.
Although not all service providers offer IPv6, there are a number of options to run IPv6 in a small network so that you can start to get experience with this new protocol. A number of “tunnel brokers” will offer early adopters a block of 264 addresses (a “/64 prefix”) or even 280 addresses (a “/48 prefix”), just for the asking. To put that into perspective, the smaller of those two blocks would accommodate a complete copy of the entire internet, even if every single node on that copy had another copy of the entire internet behind it. There are 18.4 quintillion usable static addresses in a “/64” block. Compare this to the 1 or 5 IPv4 addresses that you get from your current service provider, if you even get a globally routeable IPv4 address in the first place.
So how do you start using IPv6? Most modern endpoints support IPv6, from desktops to smartphones; you just need IPv6 connectivity activated on your LAN for them to srtart communicating. Typically, any properly activated IPv6 router will announce the configured IPv6 global prefix(“subnet”) and router address information once it has its own connectivity, and the IPV6 nodes will immediately start communicating once they detect the availability of IPv6.
The best course of action is to use your Internet Service Provider (ISP), if they can provide IPv6. For example, users of xs4all.nl and free.fr get IPv6 natively, as do users of NTT in Japan. In the United States, Comcast has a beta program (detailed at http://www.comcast6.net) whereby any users with a router supporting the “6rd” protocol can get a “/64” address pool. Cisco IOS software version IOS 15.1(3)T has 6rd support, as do modern versions of alternative firmware which run on many home routers including many popular Linksys models. Comcast provides the information needed to configure these services at the aforementioned site.
Most people will have to use a "tunnel broker" while waiting for their ISP to offer IPv6. There are three major providers that offer free IPv6 tunnel endpoints and address blocks: Hurricane Electric (http://www.tunnelbroker.net), GogoNet Freenet (http://gogonet.gogo6.com) and SixXS.net (http://www.sixxs.net). All of these providers use a range of tunneling technologies and approaches, but they will all offer free tunnel connectivity and address blocks. Each site has copious details about how to connect. Hurricane Electric uses the 6in4 protocol and provides customized sample configurations IOS. GogoNet provides a Windows application that can be downloaded to a PC and can provide robust connectivity to a single PC or a local subnet, even across NAT devices. SiXXS provides a system based on the AICCU and AYIYA protocols which can do robust auto-configuration and easy NAT traversal. All three providers are surrounded by robust communities of enthusiastic users who are willing to help newcomers!
You may read also about the 6to4 as a possible transition protocol. While it is simple to setup and supported by a number of popular home routers, real-world experience has shown that by its nature it is very fragile, and the use of it as a transition mechanism can be a source of difficult to troubleshoot issues and lower performance. We recommend you do not use it and instead get a tunnel with the broker or and ask your ISP what are their plans to support IPv6.
For more information about what Cisco is doing with IPv6, please visit http://www.cisco.com/go/ipv6 or ask your questions at http://supportforums.cisco.com.
"Use the 6to4 protocol on a supported router (http://en.wikipedia.org/wiki/6to4)" might be probably moved to resite alongside the RFC1149 - due to similar reliability issues (reliance on the unknown third party to feed the carrier of the packets ;-)
I agree: 6to4 is a risky proposition. There are those who are satisfied with the result, but there are much better ways to get IPv6. I still contend that 6to4 is fundamentally superior to RFC1149.
A good treatise on the case against unmanaged tunnels can be read here: http://tools.ietf.org/html/draft-vandevelde-v6ops-harmful-tunnels-01
I have implemented NAT64 and DNS64 and buld Wireless IPv6 using WLC 4402:
Implementation details and desgin:
https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=0B7xVT-Z06owAMGY1MDA5MGUtYjNlNy00YzE5LWE3YmQtZDhlMjYwNWY1Zjdk&hl=en_GB
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