I'll leave this bug open, because as an Ubuntu Desktop user, I would expect this to work properly out-of-the-box without installing a package or rebooting. (That is, I shouldn't have to figure out that I needed to install the "vlan" package to get it to work, as a desktop user trying to point-and-click.)
The user experience of the dialog in the screenshot is a separate concern.
I'll leave this bug open, because as an Ubuntu Desktop user, I would expect this to work properly out-of-the-box without installing a package or rebooting. (That is, I shouldn't have to figure out that I needed to install the "vlan" package to get it to work, as a desktop user trying to point-and-click.)
The user experience of the dialog in the screenshot is a separate concern.