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).

A Linux-like operating system has been installed on your VM (Rapid.Space VPS or KVM). Here we take Debian 10 Linux system as example. Make sure you have finished Redirect VPS Ports On Rapid.Space, so that you can SSH to the VM via

$ ssh your_username@ipv6_address -p 10022

This solution will setup IPv6 on ens4 interface inside your VM by modifying a configuration file. Even if you reboot your machine, the IPv6 will still be configured. 

1. Use editor (e.g. nano) as root to add the following lines in /etc/network/interfaces:

   $ nano /etc/network/interfaces

   (find following network configuration in your Rapid.Space Panel: kvm[your_VM]-ipv6-info)

   auto ens4
   iface ens4 inet6 static
     address [your_IPv6]
     netmask 80
     gateway [your_gateway]

2. run:

   $ ifup ens4

Note: This solution is specific to Debian like operating system. In other operating systems, the file to configure your network may be different, please refer to the user manual of your operating system in order to know how to configure IPv6.

This solution will setup IPv6 on ens4 interface inside your VM by running a script. If you reboot your machine, the IPv6 setup will be gone and you will need to run the command again.

Run the following command inside your VM:

$ wget -O- http://10.0.2.100/ipv6_config.sh | /bin/sh -

Note: This solution uses wget and ip commands which are widely available in Linux systems, so you should be able to use it on any Linux system.

Run the following commands in your VM:

ip -6 address show dev ens4 # You should find your IPv6 address in kvm[your_VM]-ipv6-info in the line of inet6

ip -6 route # You should see a line like default via [your_gateway] dev ens4 metric 1024  pref medium

From another machine which already has IPv6, you should now be able to ping your VM:

$ ping6 [your_IPv6]

If you have installed ssh server (apt install openssh-server) inside your VM, you can now access it with the command:

$ ssh [your_username]@[your_IP]