11.3.9 external

      (Tcl) Communicate Tcl commands between different processes based on the Tcl-DP RPC functions (optional). This command can set the machine up as a server (listening for commands) or client (sending commands) or both.

• on: Start VMD as a server on port 8639 (the number can be changed by changing the variable vmd_external_port before starting VMD as a server). This lets any process connect to VMD and send it new text commands. By default, only processes from the same machine can connect to it, but that can be changed with the host option. See the sections on external interfaces and remote control of VMD for more information on how to use this feature.
• off: Deny new external connections to be made. Old connections will still exist.
• host machinename (machinename ... ): Allow or deny new connections based on the address of the requesting machine. The format for each machine on the list is the same as dp_Host, which is based on xhost so external host + allows new connections from anyone, external host - denies all new connections, external host +foo allows connections from foo and external host -bar +128.186.7.* will allow any machine from the Florida State physics department to connect.
• connect machinename: Establish connection with a VMD\ process on the given machine. The remote process is the server and the process establishing the connection is the client.
• send command: Evaluate the command on the server process.
• close: Detach from the server.