IPv6 in a Netcup VServer

NOTE: Now that Netcup VServers support IPv6 natively, this article is obsolete and only interesting for historical and technical reasons.


I'm running a VServer from Netcup in a Hetzner Online facility in Nuremberg. This product natively offers IPv4 connectivity but no IPv6 connectivity at all. I can run a (Linux) distribution userland of my choice but the kernel is always a Linux VServer enabled kernel with certain restrictions:

With this in mind, I still wanted to establish IPv6 on this server. The basic idea is to do everything inside a UML (User Mode Linux) guest machine which can do everything necessary internally but externally doesn't do restricted actions. IPv6 access to the already existing IPv4 services will be provided via IPv6-IPv4 tunnels.

Steps taken

As a Debian Developer, I'm using Debian as the example operating VServer host and UML guest OSes, but the following should also be possible with other distributions.


The above scenario offers IPv6 access to services (e.g. HTTP, FTP, SSH, SMTP, IMAP) that would normally be available only in an IPv4 version on this VServer.


With the above steps, you can add IPv6 connectivity to a IPv4 VServer, with some minor restrictions. This is because I just extended the already existing IPv4 services on my IPv4 server with IPv6 access. It is also possible to have everything running inside the UML directly which is more flexible but also more difficult to maintain.

Roland Stigge <stigge@antcom.de>, 2010-10-23