It works!

You need to turn on the new machine and check in which order the network cards are recognized.
You edit the backup file of the old machine with the names of the interfaces in the right order you want and then perform the restore.

Either import the old config int the webgui where all the interfaces will be available. Or edit the config to match in advance as suggested.

And, yes, it's easy to make a typo. But you can always edit it again and re-import it.

Maybe that would work that way?

I wouldn't even asked that question, and done it already ^^
There is just one rule : don't make any 'errors' while editing your xml file.

I could edit the backup xml with the new interface names and their mac addresses as it expects it at startup on the new machine.
Maybe that would work that way?

@Gertjan said in Restore config - problem interface assignment:

Finish up in the GUI.

and I lose all the configuration information of the interfaces

I'm not a frequent VM user, and never saw that many interfaces ....
Not sure if its useful info, but I would assign the WAN, the LAN, and have the system started.
Finish up in the GUI.

Interface assignment on the console level is - normally - something rather rare.

@Gertjan said in Restore config - problem interface assignment:

and put them all - for this server - under :

My config is already set up like this

You can't assign an interface not known to the system at that moment.
Known are : the ones listed.
The OpenVPN server will start when the system boots normally, and the OpenVPN server process will created at that moment the 'virtual' interface ovpns1.

edit :

"Best practice" is :

Create an interface under Interfaces > Interface Assignments based upon your "ovpns1" interface.

The settings are :

so it's just the desciption - nothing else.

From now on,; you can leave the "OpenVPN" rule set empty :

and put them all - for this server - under :