Tomasz:
Regarding that scenario:
If MiNT adoption to the controller is/was via level-1 MiNT link...and now it *should* be level-2, and the WLAN is configured as tunneled....
In that case, if the APs adoption was left as being adopted using level-1 MiNT, then no issue. Tunneled traffic over level-1 MiNT. Good to go.
If the AP adoptions were changed to level-2 adoptions and the WLAN was tunneled, then yes....this would break communications. The APs would have to be setup to tunnel traffic over level-2 MiNT links. It can be done, but has to be configured.
But....even still, it shouldn't stop a client from simply associating with an AP. Worse case, the client can associate, but cannot pass traffic through the AP. But they'd still be associated, right? That's what I'm trying to figure out here....are the clients *actually* associating or not.