Dual Stack Connectivity Chart
This chart performs tests of connectivity to websites by fetching an image from that website.
Note that we don't proactively maintain this chart anymore. If you find problem, for instance this chart makes your browser try to fetch non-existent picture, or a site wrongfully categorized as not dual-stacked, please let us know at email@example.com.
What does this mean?
If you see this: All websites reached successfully. No problems reaching dual-stacked websites from this computer at this location. No further action required.
If you see this: Tests to all dual-stacked websites failed. This could be a short-lived connectivity problem, but it probably indicates that you have a problem reaching dual-stacked websites. See How to fix broken connectivity to dual-stacked websites.
If you see this: Tests to some dual-stacked websites failed. Because you could reach other dual-stacked websites, this is probably not a problem with your local computer but indicates that you may have a problem reaching a part of the Internet over IPv6. This is not something you can fix yourself, but you should contact your ISP to make them aware of the problem, and see if they can fix this.
If you see this: Tests to a single dual-stacked website failed. This is probably a short-lived problem between you and that particular website, so please retake this test and see if the problem persists. We do collect statistics on this type of failure and will contact the website owner if tests to their particular website fail significantly more often than others.
What does this chart do?
This chart helps you to test whether your computer makes the right decisions about using IPv4 or IPv6. This is important even if you do not have IPv6 connectivity at this time. Some computers' set-ups assume they have IPv6 connectivity even if they do not. This may cause problems accessing Internet services that are available with both IP protocol versions.
What do we measure?This chart performs tests of connectivity to websites by fetching an image from that website. The results for a website are:
|Content fetched within 10 seconds|
|Content not fetched within 10 seconds|
How to fix broken connectivity to dual-stacked websitesThe ARIN IPv6 Wiki has the most complete list of fixes for this problem. What follows is a short list of suggested fixes:
- Contact the help desk of your ISP and tell them you have a problem reaching dual-stacked websites
- For Windows users:
- Try to use Microsoft's Fix it-item to disable tunnel IPv6 interfaces. (direct link to this Fix it-item - 50412)
- If that doesn't work, try Microsoft's Fix it-item to use IPv4 instead of IPv6 in prefix policies. (direct link to this Fix it-item - 50410)
- For Mac OS X users:
- Upgrade to the latest version of Mac OS X if possible. Versions before 10.6.5 (Snow Leopard) have known bugs that Apple has not yet fixed.
- If there are any Windows computers in the same network, if possible turn them off, restart your Mac and repeat the test. If this solves connectivity problems, the Windows computer could very well have a feature called Internet Connection Sharing (ICS) enabled. In this case, ICS interferes with your ability to access dual-stacked websites, so please try to switch it off.
- Upgrade to the latest version of your web browser software because older versions may have known bugs.
- For a more detailed test to a single test facility, please visit http://test-ipv6.com