Configuring IPv6
Our network fully supports IPv6. But our VPS templates are configured with IPv6 disabled by default. The reason was that when IPv6 is enabled, the operating system will default to IPv6, but many hosts (including software downloads and gaming etc) though having IPv6 configured, does not work very well. Some hosts have IPv6 DNS addresses but the actual address is not optimally announced through IPv6 BGP, causing timeouts before falling back to IPv4. This causes long delays especially tasks like software download and installation.
But your application may be different and could benefit from IPv6. To enable IPv6 manually,
CentOS
1. Edit the interface config file in /etc/sysconfig/network-scripts/ and add these two lines at the bottom
IPV6INIT=yes
IPV6_AUTOCONF=yes
2. Edit /etc/sysctl.conf and remove all lines with "disable_ipv6 = 1"
3. Reboot
Ubuntu / Debian
1. Edit /etc/default/grub and remove all "ipv6.disable=1", so that the two lines become
GRUB_CMDLINE_LINUX_DEFAULT=""
GRUB_CMDLINE_LINUX=""
2. Run "update-grub"
3. Edit /etc/sysctl.conf and remove all lines with "disable_ipv6 = 1"
4. Reboot
Windows
1. Run "regedit"
2. Set the registry key value HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6\Parameters\DisabledComponents to 0
3. Reboot
Adding IPv6 Addresses
After configuring and rebooting the server, you will see one automatically assigned IPv6 address.
Linux command: ip -6 address
Windows PowerShell: Get-NetIPAddress -InterfaceAlias "Ethernet" -AddressFamily IPv6
The automatically assigned IPv6 address will look something like the example below (run the commands above to view your actual address):
inet6 2401:300:0:2:5555:58ff:fe06:8888/64
In this address, the segment ff:fe is fixed for the auto‑assigned address.
When adding a new address manually, you can replace ff:fe with any value from 00:00 to ff:ff
Examples:
2401:300:0:2:5555:58ff:ff06:8888/64
2401:300:0:2:5555:580a:0a06:8888/64
2401:300:0:2:5555:581b:2b06:8888/64
2401:300:0:2:5555:5800:0006:8888/64
All of these addresses are valid.
Linux — Add an IPv6 Address
ip -6 addr add 2401:300:0:2:5555:58ff:ff06:8888/64 dev eth0
(Replace eth0 with the actual interface name shown by ip -6 address.)
Windows — Add an IPv6 Address
New-NetIPAddress `
-InterfaceAlias "Ethernet" `
-IPAddress "2401:300:0:2:5555:58ff:ff06:8888" `
-PrefixLength 64 `
-AddressFamily IPv6
