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. See client max protocol for a full list of available protocols. IPC$ connections for DCERPC e.g. in winbindd, are handled by the option. client max protocol server min protocol client ipc min protocol client ipc max protocol CORE NT1