Introduction to IPv6 and Virtualmin
For a background on what IPv6 is, see http://en.wikipedia.org/wiki/IPv6 . Virtualmin has the ability to create domains that have IPv6 addresses in their DNS zones, and accept v6 connections to their websites. Naturally, this functionality is only useful if your system has an IPv6 connection to the Internet, which is not the case for all ISP and datacenters.
Currently only CentOS, Redhat, Fedora, Debian and Ubuntu Linuxes are supported for IPv6 configuration by Virtualmin. Other distributions and operating systems don't yet have the required support, even if they can be manually configured to handle v6 networking.
Each virtual server has the option of either not having an IPv6 address at all, using a shared address, or having its own private IPv6 address. Because the global number of available v6 addresses is 10^28 times higher than IPv4, it should be possible for every domain to have its own address. However, not all ISPs and data centers actually offer their customers multiple addresses - if you are in this situation, name-based shared hosting on a single address is supported by Virtualmin.
In all other ways, IPv6 allocation and use in Virtualmin behaves exactly the same as IPv4. It is even possible for a system to have a shared v4 address and private v6, or vice versa. Although we don't recommend this, as it can make diagnosing SSL certificate problems difficult.
Preparing To Use IPv6
In order to use IPv6 with Virtualmin, your system should have a static v6 address on its primary network interface (typically eth0). This will normally be provided by your ISP or hosting company, and can be set at Webmin -> Networking -> Network Interfaces -> eth0 . The netmask and IPv6 default router can also be set in the same module.
If your ISP has provided a range of IPv6 addresses for your system to use, they should be entered at System Settings -> Server Templates -> Default Settings -> Virtual IP address , in the Ranges for automatic IPv6 allocation field. Virtualmin will then pick a free address from this range when creating a new domain.
Adding a Domain With an IPv6 Address
When creating a virtual server on an IPv6-enable system, the IPv6 network interface field in the IP address and forwarding section determines if it will be assigned an allocated private address, a shared address, or no IPv6 address at all. By default new domains do not get a v6 address, but you can change this at System Settings -> Virtualmin Configuration -> Use default IPv6 address for new virtual servers?.
Virtualmin supports multiple shared IPv6 addresses, which can be configured at Addresses and Networking -> Shared IP Addresses. You can also set a default address for resellers to use for their domains on the Edit Reseller page. In both cases, the entered addresses must be already active on your system.
Changing the IPv6 Address
Once a virtual server has been created, its IPv6 address can be changed, added or removed at Server Configuration -> Change IP Address . Changes to multiple domains at once can be made using the Change IP Addresses page, under Addresses and Networking.