Poofdirtpirate Ipv4 and Ipv6 make no difference in terms of attack surface, Ipv6 is simply a much more recent protocol at layer 3 of the OSI model, designed to meet the shortage of Ipv4 addresses, Its length is 128 bits compared with 32 bits for an Ipv4 address, so you can use an Ipv6 address without any problem. It may happen that Ipv6 is not enabled by default at your VPN provider, simply because it's not necessary for routing traffic.