On September 02, 2015, John Graham-Cumming announced that CloudFlare had switched on a test server to allow users to check the compatibility of their web clients with IPv4/IPv6, HTTP/2, and an SSL certificate using SHA-2 for its signature. The server was intended for testing purposes only and used three key technologies: IPv4/IPv6, HTTP/2, and a SHA-2 based SSL certificate. This test site aimed to provide users with an HTTP/2 endpoint to test their client software compatibility.