An observation while you await a sensible reply. This seems to be a complicated interaction involving Netbios names, possibly DNS, samba on Freenas and CIFS/SMB on windows: I'd just be grateful that it works at all. I see no harm in mapping network drives using //freenas. If it fails one day you can go back to IP addresses. Seriously, if you want something to be reliable, or work in a script, I would use the windows syntax (which involves \\ but otherwise I've forgotten) for a network connection, using the IP address, rather than a mapped drive. Mapped drives often seem to fail to connect for no obvious reason.