In the past few months, we have gradually enabled IPv6 for all user-facing services in Dropbox edge network. We are serving about 15% of daily user requests in IPv6 globally. In this article, we share our experiences and lessons from enabling IPv6 in the edge network. We will cover the IPv6 design in the edge, the changes we made to support IPv6, how IPv6 was tested and rolled out to users, and issues we encountered. Note that this article is not about enabling IPv6 for internal services in our data centers, but rather focuses on making IPv6 available to users.
Computers on the internet are uniquely identified by an IP address. For decades the world has used Internet Protocol version 4 (IPv4), which allows for about 4 billion unique addresses. As more of the world has come online, and we carry internet-capable devices in our pockets, we have run out of IPv4 addresses. Layers and layers of workarounds have been built to mitigate the problem. The current protocol—Internet Protocol version 6 (IPv6)—fixes various problems with IPv4; it has a significantly expanded address space that allows for the creation of many more unique IP addresses. Unfortunately, IPv6 has suffered from lack of adoption.