Rapid.Space provides IPv6 connection on all servers. IPv4 is too expensive, because of limited address space. Your server and VM are thus allocated a /64 block of 18,446,744,073,709,551,616 routable IPv6 addresses which can be contacted from anywhere in the world through any TCP/IP protocol over IPv6. Your machine can also be contacted through HTTP or HTTPS over IPv4 thanks to Rapid.Space Content Delivery Network (CDN) which acts as a proxy between HTTP(S) over IPv4 and HTTP(S) over IPv6. This is for example how the Nexedi web site is accessible to all IPv4 users although its backend is hosted by Rapid.Space on an IPv6 only network. IPv6 is becoming increasingly adopted worldwide. It should thus be quite easy to find an IPv6 compatible ISP. IPv6Droid provides quite reliable IPv6 on Android about anywhere in the world. In China where IPv6 adoption is still low, Grandenet provides resilient IPv6 connectivity compliant with Chinese Laws.
Your server and VM can access any IPv4 reachable host through any TCP/UDP based protocol (ex. HTTP, QUIC, SSH, stunnel, etc.) that supports Network Address Translation (NAT). Your server and VM can access any IPv6 reachable host through any TCP/IP protocol (TCP, UDP, 6in4, GRE, etc.).
This tutorial will explain how to install IPv6 inside your VM. There are two ways to install: the permanent solution (suggested) and the temporary solution which will not last after reboot. At the end, the tutorial will verify the setup. After IPv6 is installed inside your VM, you can do remote access to your VM if you have IPv6 on your machine (if you don't have IPv6 on your machine please follow HowTo Install IPv6 On Your PC).