client min protocol

This setting controls the minimum protocol version that the client will attempt to use.
Normally this option should not be set as the automatic negotiation phase in the SMB protocol takes care of choosing the appropriate protocol unless you connect to a legacy SMB1-only server.
See client max protocol for a full list of available protocols.
IPC$ connections for DCERPC e.g. in winbindd, are handled by the option.
Note that most command line tools support --option='client min protocol=NT1', so it may not be required to enable SMB1 protocols globally in smb.conf.

Example: NT1

Supported on: At least Microsoft Windows 7 or Windows Server 2008 family

client min protocol

Registry HiveHKEY_LOCAL_MACHINE
Registry PathSoftware\Policies\Samba\smb_conf\client min protocol
Value Nameclient min protocol
Value TypeREG_SZ
Default ValueSMB2_02

samba.admx

Administrative Templates (Computers)