The Term IPv6 refers to the Internet Protocol Version 6 which can be considered as an upgrade over the earlier Internet protocol Version i.e. IPv4.
For establishing a secure connection over the internet every devices which are connected to the internet requires a unique IP address which facilitates the identification of the sender and receivers in an active session. The immense increase of the internet users simultaneously results into the increase in the no. of the internet enabled devices which is the main reason behind the evolvement of the IP addresses. The previous protocol IPv4 finds it difficult to manage such bulk no of users. That’ why the Internet Engineering Task Force (IETF) was forced to develop an updated protocol i.e. IPv6 to cope up with this massive growth.
Being 32 bits long though the IPv4 is recently carries 4.3 billion unique IP addresses, the IPv6 evolved to serve more efficiently. That’s why it’s have 128 bits length and a capacity to stagger unique IP address of 3.4×10^38.
Hiding the original IP address is one of the most important aims of every VPN connection to keep the user protected from any kind if data theft as well as security risk. Though IPV4 protocol is being used for a longer time period than the Ipv6, that’s why most of the VPN services (e.g. ExpressVPN and many others) are specially configured for the Ipv4 protocol. For this reason, keeping IPv6 protocol enabled while using a VPN who encrypts IPv4 protocol may result into the leakage of the IPv6 protocol. It is expected that though the IPv6 protocol is being popular day by day, we will surely get IPv6 compatible VPN services in the near future. Though most of the networks do not support IPv6 protocol, disabling the IPv6 protocol will surely be the wise decision to keep you protected from every aspect.