August 01, 2003

Global IPv6 adoption

One of the hottest topics today in the networking world is that of IPv6. The newest version of the Internet Protocol has been in development over the last ten years or so, and will hopefully replace IPv4 as the standard addressing scheme for all internet enabled devices. IPv6 is designed primarily to address the issue of the scarce IP address space that plagues IPv4.

But will IPv6 be adopted by the masses and take over as the primary protocol for internet communications?

The problem with IPv4 is that it has a total address space of around 4 billion addresses, with a practical limit of 250 Million devices. Given that around 1 billion people have easy access to the Internet, it's easy to see that there just isnt enough space for everyone. Plus multiple devices for each person. This scarcity of address space has resulted in several ways to overcome this:

  • Strict allocation policies, so that addresses are only given out based on the number of devices that will be connected. So a requirement for four devices, for example, will result in being allocated four addresses. And you have to really want to have these devices connected.
  • Network Address Translation is a scheme that allows many computers located behind a gateway to all access the internet. The non-routable addresses behind the gateway are translated to a routable address on the gateway so that a single IP address can allow dozens or hundreds of machines to access the internet. This is a bit of a hack however, and breaks many applications which require direct connectivity between devices.

With these basic limitations, management of networks becomes complex, and adoption of new technologies is stifled. One of the most promising new technologies is voice over ip. This enables one to conduct voice conversations over the net, essentially bypassing the phone companies and eliminating phone call costs.
But VoIP requires direct connectivity betwee endpoints, which is very complex when NAT is involved. And the scarcity of IP addresses makes getting addresses for these "IP telephones" difficult. Thus VoIP will have a slow adoption rate.

IPv6, on the other hand, has a huge number of addresses available. Not 4 billion, but some number too large to write in words. The actual number is 340,282,366,920,938,463,463,374,607,431,768,211,456! To compare, IPv4 has 4,294,967,296 addresses. With this many addresses, IPv6 has enough for every household in the world to receive trillions and trillions of addresses. So with ample space, any device is freely able to connect and obtain full connectivity to the internet without complex justification and messy NAT schemes.

The potential uses with appliances, peer to peer applications, and gaming are quite numerous, and the speedy adoption of IPv6 is necessary to take the internet to its next level.

But will people adopt it soon? The IPv6 community is quite small, however it grows each day, and it seems to have accelerated over the last year. There are more and more networks that are supporting IPv6, and fairly soon most networks will support it. However, native IPv6 connectivity for consumers may be sometime off. Many providers are uncertain as to the stability of installing IPv6 on their access networks. Indeed, much of the access gear avaialble today has little production quality IPv6 support so the upgrades may cause other instabilities. Without testing, it will take longer to iron out any bugs. Providers must be willing to test this now, or risk being left behind.

Many providers also seem to be scared of offering consumers full internet access. There are some TOS agreements around that restrict what can be done with the connection (eg no servers, one computer, etc) which completely conflict with the spirit of IPv6. Providers will need to be willing to offer the standard /48 allocation of address space (as recommended in RFC3177) and to permit full connectivity in and out. If restrictive providers simply give a single IP address or a single subnet, then that will severely limit the potential uses for IPv6. Fortunately most providers that I know of in Europe are planning on providing a full /48 to subscribers - as to whether this policy is adopted by US and Aussie providers is yet to be seen.

At the same time as providing network readiness, there also need to be applications that support IPv6. At the moment the application support is quite extensive. Many web browsers, email applications and news readers support IPv6. However, on the whole, most applications do not support IPv6. Peer to peer applications and IM programs are currently IPv4 only. Once these are ported to IPv6, then the adoption rate should increase significantly. Porting to IPv6 is usually incredibly simple, with just a modification to the socket sections of the code. These applications will then work on both IPv4 and IPv6 at the same time.
There are a few applications for which it gets a lot more complex, with data file formats and various other sections of the code requiring modification, but overall it can generally be done with little overall impact on the program. Coders should be encouraged to ensure Ipv6 support is in their applications, which will help to spread the adoption of the protocol everywhere.

As of this time, IPv6 support is available in most Linux distributions, Mac OSX, and all windows versions from WinXP upwards. It's ready to run and we should start using!

Everyone who can should do the net some good and adopt IPv6 in their networks and applications. By offering full support for the protocol, the benefits of it can be realised sooner by all. I for one am doing my part, having set it up on my home boxes, and started rolling it out on the network at work. With 1.5 million users on this network, I'm hoping this has a large impact for the adoption of IPv6.

For those without native IPv6 connectivity, all operating systems that support IPv6 can get connectivity via tunnels. A quick search for ipv6 tunnel broker will come up with various sites to get your own tunnel and subnets.

More information is available from:

Posted by Ben at August 1, 2003 04:49 PM


I've been compiling a list of IPv6 accessible websites:


Posted by: Sander at August 13, 2003 10:54 PM
Post a comment

Remember personal info?

Recent Entries
- Linux on an HP Compaq NC6400
- Sodium in water? Bah..try Caesium!
- I'm off to Lugradio
- Food for thought...
- Replacing ugly Helvetica fonts in Xorg
Support me...

Email me:
NL time:03:23
Book: Assassini (Thomas Gifford)
Amazon wish list
Search the web