This command was introduced in the LAN Manager 1.0 dialect. The formats of the request and response messages have changed since the command was first defined. The CIFS format, as defined for the NT LAN Manager dialect, is presented here. This format MUST be used when the NT LAN Manager dialect has been negotiated.

This command is used to configure an SMB session. If the server is operating in user level access control mode, then at least one SMB_COM_SESSION_SETUP_ANDX MUST be sent in order to perform a user logon to the server and to establish a valid UID.

In CIFS, it is a protocol violation to issue an SMB_COM_TREE_CONNECT or SMB_COM_TREE_CONNECT_ANDX request before an SMB_COM_SESSION_SETUP_ANDX command has been successfully executed, even if the server is operating in Share Level Access Control mode. Including an SMB_COM_TREE_CONNECT_ANDX batched request in an AndX chain (section following an SMB_COM_SESSION_SETUP_ANDX request is sufficient to fulfill this requirement.<90> Anonymous authentication is also sufficient to fulfill this requirement.

Multiple SMB_COM_SESSION_SETUP_ANDX commands are permitted within an SMB connection, either to establish additional UIDs or to create additional virtual circuits.

The following are the commands that can follow an SMB_COM_SESSION_SETUP_ANDX with an SMB_COM_TREE_CONNECT_ANDX (section in an AndX chain: