NuevaSync Blog
Tuesday May 31, 2011

Sync On World IPv6 Day

You've probably heard that the Internet has recently run out of unused addresses. There are some good pages explaining the full history, but the current IPv4 address space exhaustion was foreseen long ago. I was present at Scott Bradner's initial presentation to the November 1993 IETF meeting and as I recall at the time the concern was that Microsoft's new consumer desktop Operating System (Windows95) would include Internet networking. It was thought that this alone could use up all the remaining addresses within a few years. It turned out that Network Address Translation (NAT) was subsequently widely deployed, which delayed the process by at least decade, but finally in 2011 the address space is all used up. The solution, developed under the IETF working groups established as a result of Scott's talk is IPv6. It includes support for a much larger address space. So large that there is no practical possibility of running out of addresses (ever). IPv6 has been available in most operating systems, routers and servers for many years but unfortunately has for the most part not been used. The reason for this lack of adoption is that ISPs have not shown much interest in making IPv6 available. This makes sense since they have plenty of addresses themselves! But with all the IPv4 addresses now used up, the time has come to take action:

ISOC's World IPv6 Day

The Internet Society has organized World IPv6 Day in conjunction with a number of large web properties and network operators. NuevaSync has signed up as an active participant. This means that on June 8 our main sync service "endpoint", and all our web site facilities will be accessible using IPv6. This is a little different, and more ambitious than simply being "IPv6-reachable" with a special host name. It means that mobile devices and web browsers accessing our services will automatically select IPv6 to communicate with our servers, if it's available on that day. Of course if a device does not have IPv6 connectivity it will use regular IPv4 as usual–it'll still work as before. If there are no significant problems discovered on "World Day", the plan is to leave our IPv6 support in place on an ongoing basis.

Prior to June 8 we have IPv6 available using the host name:
Our web site, including the control panel is IPv6 accessible :
Devices can be configured to sync to this server:
(but please be sure to read the warnings below before you configure a device to sync with this server).

Can you use IPv6?

If you'd like to try IPv6 the first task is to check for connectivity from your computer and mobile devices. We've found this test site be the best way to do that. Most Windows 7 computers will have IPv6 thanks to automatic tunneling (which works even if your ISP does not directly offer IPv6 service). However for mobile devices the picture is somewhat patchy. First, we have yet to find a local mobile network provider here in the USA offering IPv6 (although there is a rumor that Verizon has it on their LTE service and T-Mobile has a beta test program underway). So our testing was done using WiFi. None of the devices we tested supported automatic tunneling so you will need "real" IPv6 on your network. Since our ISP at the office does not yet offer IPv6 (boo, hiss...) the NuevaSync HQ is using Hurricane Electric's free IPv6 Tunnel Broker service (which has worked well for demos and testing). Second, not all devices have fully functional IPv6 support. For example here's the test result for a Samsung Android 2.2 phone. It has IPv6 support, but for some reason does not perform the necessary AAAA record DNS lookups (Another Android phone from HTC tested ok):

Android IPv6 Test
However, Apple device owners are in great shape. All our iOS4 iPhones, iPads and iPod touches pass the test:

Apple IPv6 Test 

How to test IPv6 with NuevaSync

The web site is only reachable using IPv6 so if you can load the site, that means your browser can use IPv6.
To check to see if a device is using IPv6 for its sync connections just look at its sync scope page on our control panel site. You should see the IPv6 address format with ":' characters as shown in the screen shot below:

Sync scope screen shot showing IPv6 device address 

A Warning for IPv6 Testers

There is one issue to beware of when testing sync using the server name (this won't be a problem when the main host name is IPv6-enabled). Don't configure one device to sync with both and at the same time. This will typically give strange (and not good) results because the device sends the same "unique" id to both servers. In reality the two host names end up at the same cluster of sync servers and as a result will not function properly (the split-personalities of the device will fight, continually triggering resyncs in each other). To avoid this pitfall just turn off one sync account on the device, or use two different NuevaSync accounts.

IPv6 Information and Status Pages

The NuevaSync wiki now has pages listing the current status of mobile device support for IPv6 and any information we collect on the availability of IPv6 from public network providers.

Special thanks are due to Silicon Valley Colocation for providing our servers with IPv6 addresses quickly and painlessly.

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