Bitbucket Cloud: now available over IPv6

By on July 21, 2016

Just after 18:00 UTC 19 July 2016, we published our first set of AAAA records in DNS, making and its associated hostnames available to the world over IPv6. We’re taking a dual-stack approach here, so IPv4 addresses will continue to work for the foreseeable future – but any IPv6-only systems you manage will now be able to access Bitbucket APIs and repos, and any systems that work with both IPv4 and IPv6 will have additional routing options which may improve network performance. This also makes it easier for us to handle new networks and clients, especially as new IPv6-only systems come online.

IPv6 traffic picked up as soon as DNS servers started seeing AAAA records IPv6 traffic picked up as soon as DNS servers started seeing AAAA records.


Most people will not have to do anything different to use our IPv6 addresses: in fact, if your local network and ISP both support IPv6, then you may already be using IPv6 to reach Bitbucket. However, some people may need to update their firewall configurations to permit the following destination IPv6 addresses for

Firewalls should also permit the following destination IPv6 addresses for

These addresses are listed alongside their IPv4 equivalents in our public documentation. We’ve also added IPv6 support for, 2401:1d80:1010::15f and 2401:1d80:1003::15f, in case you need those, and set up forward and reverse DNS for all of our allocated IPv6 addresses.

Our IPv6 work started as a ShipIt project by some members of our Network Engineering team, using a proof-of-concept implementation on Bitbucket in a live demo. We had to perform a number of network and infrastructure upgrades (including new IPv4 addresses) before we could start using IPv6 for real, but once those upgrades were done we moved pretty quickly through testing, preparation, and deployment.

The best part of this whole IPv6 rollout, though, is that nobody would have noticed it if we hadn’t said anything. The Happy Eyeballs algorithm has done much of the heavy lifting here, seamlessly moving millions of sessions to IPv6. Our support team has seen a couple of tickets about IPv6-specific routing difficulties, but they were able to resolve or work around the issue within minutes. (If you’re also having problems due to IPv6 routing, then please contact us at for assistance.)

We’re very glad that this has gone so well, and that we can take the lessons we’ve learned deploying IPv6 to Bitbucket and apply them to other Atlassian products. Stay tuned for more updates on infrastructure projects!


  • Posted July 22, 2016 at 4:56 am | Permalink

    And host is an alias for has address

    • Posted July 22, 2016 at 10:48 am | Permalink

      Yes, that’s true. As you can see from that CNAME, we aren’t hosting this blog in-house; we’re also not hosting our DNS or CDN in-house, and we’ve only brought our status page in-house in the past week or so.

      I’d love to have our full complement of services available on IPv6 right now, but it’s non-trivial to move some of these third-party services. Better to do what we can now, and then bring the rest up to speed somehow.

      • Ross
        Posted July 23, 2016 at 1:35 am | Permalink

        Sounds like bitbucket need to look for another blog host that can keep up with the evolving Internet. That IPv4 is a rackspace IP and rackspace have supported IPv6 for a long time.

        • Posted July 25, 2016 at 11:40 am | Permalink

          WPEngine supports IPv6, but this blog shares its account with several other Atlassian blogs. I’m already working on getting those other blogs on-board with a dual stack, but (as I said above) it isn’t trivial.

          In the meantime, though, you can use Bitbucket over IPv6.

          • Ross
            Posted July 26, 2016 at 8:58 am | Permalink

            And congrats on getting Bitbucket over IPv6, that is the main achievement. Believe me I know about the difficulties of turning on IPv6.

  • Posted July 24, 2016 at 5:17 pm | Permalink

    I noticed when I saw:

    Warning: Permanently added the RSA host key for IP address ‘2401:1d80:1010::150’ to the list of known hosts.