It’s IPv6 day today. Great, so what?

8 Jun 2011

OPINION: Jim Foster, client principal at BT Ireland, explains why IPv6 is such a big deal, why it matters to the IT industry and why there’s no need to panic in the same sense as the panic that gripped the industry in light of the Y2K bug.

Without much in the way of public fanfare, those in the know in the world of the internet protocol will be ‘celebrating’ today (8 June 2011) by participating in a global test drive of IPv6. This will involve major ISPs, equipment manufacturers, enterprises, web companies – Google, Facebook, Yahoo, Cisco and BT among many others – ‘switching on’ IPv6 for 24 hours.

This follows extensive development and testing of IPv6 on a test network called the 6-bone. IPv6 has been developed over the last 10-12 years by the IETF (Internet Engineering Task Force) as a replacement for the current internet protocol IPv4.

Why is IPv6 so important?

There are several important advantages of v6 verses the current v4, but the most important of these is that v4 is rapidly running out of addresses. Imagine the reaction if you signed up for broadband only to be told by your ISP, “Sorry, we’re out of addresses so you can’t access the internet.”  This simple example could be applied across all organisations – government, military, commercial, etc. Something had to be done – so IPv6 was born.

Happily, unlike the panic that gripped the IT industry over the Y2K bug, the issue of rapidly diminishing address space has been known for many years and IPv6 has been in development and testing during those intervening years to ensure a smooth transition. Set against this, though, is the explosion in the amount of devices requiring IP addresses. Think of the millions of mobile devices, various consumer electronics and even white goods, such as high-tech fridges, are now coming with an IP stack and require addresses.

Some techniques, such as network and port address translation, were developed that delayed the deadline, but were never intended to be long-term fixes.

What does an IPv6 addresses look like?

Let’s start with the familiar IPv4 – it has a 32-bit address space. A typical example would be:

IPv6 has 128-bit address space. A typical example would be:


To gain some understanding of the increased address space – this means that IPv6 has 2 to the power of 128 or approximately 3.4 x 10 to the power of 38 addresses. Mind-boggling numbers – think of it this way – enough to assign an internet address to every gram of matter on the Earth and moon!

It’s not the intention of IPv6 to saturate the globe with addressing, however. Most of the address space will be used to simplify how the addresses are allocated, provide routing efficiency, and additional special use addresses.

Other headline benefits of IPv6 are:

  • Subnet size is standardised – by fixing the host portion of an address to 64 bits
  • Simplifying address assignment and network renumbering
  • Improved security – IPv6 mandates the support of IPSec for fundamental interoperability

Will internet users be affected on World IPv6 Day?

The vast majority of users will be unaffected – it’s expected that about 0.05pc of users may experience problems. Participating organisations will be working together with operating system manufacturers, internet service providers (ISP), etc, to minimise the number of users affected.

One of the main aims of the IPv6 Day ‘test drive’, however, is to expose potential issues under controlled conditions and then fix them as soon as possible.

Participating organisations are not going to turn off IPv4 on the day – it will run it in parallel with IPv6. IPv4 will still be available, so absolutely no need to panic. IPv6 day is a 24-hour test that will also be used to raise awareness of the IPv6 project.

Can I test my own IPv6 readiness?

You can use this URL – from the global Internet Society – to test IPv6 readiness from your host device:

BT was one of the pioneers in deploying IPv6 in Europe in partnership with UK academic networks. For many years, we operated the UK6X Internet Exchange for IPv6 traffic, so we are well prepared to provide a smooth transition and fully support the IPv6 day activities.

During the 24-hour event we will make BT content reachable via IPv6 addresses for internet users across the world wishing to take part.  We’ve also collaborated with a key European customer to v6 enable their website content for World IPv6 Day and beyond. To learn more go to the website.

On the day, along with other ISPs, we will also enter a heightened alert status to assist quickly with any IPv6 issues that crop up during the test drive.

For most of you, IPv6 will be indistinguishable from services delivered using IPv4 and make no difference to the service you receive. In Ireland, our national core IP network is already 100pc IPv6 capable, and we will support you whether you are connected via IPv4 or IPv6 for many years to come.