We are proud to announce that LinkedIn has launched IPv6, the next-generation internet protocol. Beginning today, people can connect over IPv6 to www.linkedin.com from any IPv6-enabled endpoint: laptop, desktop, mobile phone, tablet, or the developer API. LinkedIn will continue to provide IPv4 connectivity in order to serve all our members.

IP addresses allow a device to connect to the Internet. IPv4 is the old internet protocol that is rapidly running out of internet addresses with the Internet’s explosive growth. When the IPv4 protocol was written, Internet engineers did not imagine that so many devices would connect to the Internet, so they created an address space that was 32-bit or 2^32, which equates to approximately 4.3 billion addresses. There are over 3 billion users on the Internet, and most users have multiple Internet-enabled devices, so you can do the math to figure out that we will run out of IP addresses soon. Asia has already exhausted all of its allocated IPv4 addresses, and North America and Europe will soon run out as well.

To solve this problem, the good folks at IETF formalized a new protocol, IPv6, to provide 2^128 or 3.4 x 10^38 (340 undecillion) IP addresses. The scale of IPv6 addresses is such that you can assign an IP address to every atom on the surface of Earth and still have IP addresses left over for 100 more Earths.

The transition to IPv6 is invisible for our members. Your browser will automatically connect to the Internet over whichever internet protocol a member’s ISP provides. If you wish to see whether you’re visiting www.linkedin.com via IPv6 or IPv4, download one of these browser tools: IPvFox (Firefox) or IPvFoo (Chrome).

If you are using IPvFoo on a Chrome browser, you should see something like this. Note the number 6 on the right side of the URL -- this means you are visiting www.linkedin.com via IPv6.

If you want to look under the hood in advanced mode, right click on a LinkedIn page and click on Inspect Element. This will expose the HTTP header where you can see that we are serving an IPv6 address to you. It should look something like this.

Rolling out IPv6 at scale was not a trivial task. Our IPv6 task force has worked for a year to ensure today’s smooth addition of IPv6 connectivity. We did many code changes and a series of production tests along the way, including a recent 42-hour global test where we saw approximately 3 percent of members visiting LinkedIn services via IPv6. The IPv6 task force was a collective effort of many talented individuals across engineering and operational teams. I am honored to be working alongside such talent ensuring that we stay ahead of the curve by adopting IPv6.

We encourage more content providers and ISPs to deploy IPv6 and join the next generation of the Internet.