On World IPv6 Day, CloudFlare observed a steady growth in IPv6 usage across its network. The majority of IPv6 traffic comes from legitimate users on mobile networks, but attackers are also starting to launch attacks over the protocol. Since 2013, IPv6 connections as a percentage of total traffic have grown by 26.5%. However, even with exponential adoption rates, it will take until 2020 for IPv6 connections to surpass IPv4 ones. CloudFlare supports both IPv4 and IPv6 and plans to continue doing so until the full retirement of IPv4. Additionally, IPv6-based DDoS attacks have been observed but are currently modest in size.