With the impending depletion of the global IPv4 address pool, Internet Service Providers are rapidly working on their IPv6 deployment plans. Organizations who are starting their IPv6 transition plans are asking their current ISPs about their IPv6 services. However, organizations that have chosen Tier 1 ISPs for their Internet connectivity may be surprised by these Tier 1 providers' upstream IPv6 connectivity.
Current estimates show that there are less than 300 days until IPv4 address depletion occurs. There have been many articles on Network World about how service providers are hearing fire alarms regarding their IPv4 addressing limitations. The ISPs are panicking and feverishly working on their IPv6 deployment strategies. John Curran, CEO of ARIN, has said that the next 18 months will be a critical time for ISPs to show that they can adapt to a world with IPv6. Verizon has also said that they are getting inundated with interest from their customers inquiring about their IPv6 capabilities. We are all familiar with how Comcast has taken an aggressive approach with their IPv6 beta program and has recently connected their first corporate customer with IPv6. T-Mobile has also recently started an IPv6 beta program for customers with Nokia 5230 Nuron, E73, or N900 phones.
Many enterprise organizations are starting to establish internal projects to figure out their game plan regarding IPv6. In addition to performing an IPv6 capability inventory of their existing hardware and software, they are also figuring out their Internet connectivity strategies. Organizations are contacting ARIN and their service providers to request IPv6 address space so they can begin their IPv6 addressing plans. As they are contacting their existing service providers they are starting to discover that those companies may not have a great story to tell regarding IPv6. They are starting to investigate their ISP's IPv6 peering and finding that it is limited. Last year I wrote a blog about how to choose an IPv6-capable ISP.
What customers are finding is that their current ISPs may have great IPv4 backbone connectivity but very weak IPv6 backbone connectivity. Some of the larger IPv4 ISPs do not have equivalent IPv6 peering to connect their customers closer to "the center of the IPv6 universe". Many of the Tier 1 service providers currently only advertise tens or hundreds of IPv6 prefixes and only have tens or hundreds of IPv6 Transit ASNs. Methods for checking an ISPs IPv6 connectivity include checking the IPv6 CIDR REPORT and the BGPmon - IPv6 BGP Weathermap. Therefore, you cannot just assume that your Tier 1 ISP is a Tier 1 ISP when it comes to IPv6. Furthermore, you may consider a different IPv6 ISP than the ISP you currently use for IPv4 Internet connectivity.
There are other ISPs who are looking toward IPv6 as a way for them to jump ahead of the big boys and build well-connected IPv6 networks. We could very well see a shift in the makeup of Tier 1 ISPs as organizations make the shift to IPv6 in the next 10 years. If you looked at a service provider like Hurricane Electric (AS6939) you would find that they are advertising 1384 prefixes and 948 transit ASNs. This is an order of magnitude better than other providers. I would consider Hurricane Electric (HE) to be a Tier 1 service provider when it comes to IPv6. If you use Hurricane Electric for your IPv6 Internet connectivity you will have much better reachability to the rest of the IPv6-enabled Internet.
Hurricane Electric recently updated their IPv6 Progress Report to include some new statistics that you may be interested in. The world now has over 3000 IPv6 prefixes in the Internet routing tables. Almost 2500 of the 35684 IPv4 networks are now using IPv6. There are over 3000 IPv6 glue records in the Top Level Domain DNS zone files. Over 2000 of the Alexa Top 1 million websites now use IPv6.
There are other sites that also provide a view into the global adoption of IPv6. My friend and coauthor Eric Vyncke has a nice page that shows his research that shows that Europe is ahead of North America and Asia when it comes to actual IPv6 deployments. Eric also did a NWW blog post discussing his findings and providing a list of other similar surveys.
As you are planning your organization's transition to IPv6 you should consider your ISP's capability to connect you to the "whole Internet". That means you should have an ISP that can connect you to the IPv4 Internet and the IPv6 Internet. If your current ISP can only connect you via IPv4 then I would suggest that you look at alternative service providers that may have IPv6 connectivity that eclipses those service providers who you have traditionally thought of as Tier 1 ISPs.