RTNETLINK answers: "File exists" when trying to allocate a new private IPv6


I’m just moving my Virtualmin GPL installation to a new root server under Ubuntu 14.04.1, and most things work ok, but I’m having trouble with IPv6.

I added the range available in the Server Templates -> Default Settings -> Virtual IP address, but when I try to modify one of the virtual servers to use one via its “Change IP Address” options, I get the error message:

Failed to change IP address : Failed to add IPv6 address : RTNETLINK answers: File exists

Apparently this means the IPv6 is already in use, but I can’t see where that would be (I also manually tried various numbers out of the available range)

Virtualmin gets as far as adding the IPv6 in the “network interfaces” because it shows up there when I go to Webmin -> Networking -> Network Configuration -> Network Interfaces

But it’s not retained in the virtual servers settings because of the error message.

Many thanks for any insights!

Hello again,

The problem went away this morning after upgrading Webmin to 1.710