It doesn't work. It gives me a parsing error I've tried that command even with vers=1.0 and it doesn't work. I have to put it in this format:
//192.168.xx.xxx/shares/xxxxxx /media/xxxxxx/ cifs vers=1.0,credentials=/home/username/.plexcreds,iocharset=utf8,sec=ntlm 0 0
The above works like a champ. I just don't understand why I'm stuck with SMB 1.0. The above line works perfectly, but if I change it to 2.0, 2.1 or 3.0 they all don't work. This is what I get if I try anything but 1.0:
mount error(22): Invalid argument
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs) and kernel log messages (dmesg)
you mentioned max protocol, but I would have thought min_protocol is what I should adjust to force clients to only use higher versions... I guess that still may not help as Ubuntu doesn't seem to work on higher versions. I do have the latest version of Ubuntu desktop (20.04.3 LTS) on the one that's giving me a problem.
Could it be something I did wrong on the napp-it side?
I checked from a Windows 10 machine and it shows that it does connect via 3.1.1.