Start the appropriate subsystems before you start TCP/IP.
QSYSWRK and the controlling subsystem are always started for you by the operating system. QUSRWRK and QSERVER are started by the IBM-supplied startup program, so unless you have changed the IBM-supplied startup program these subsystems should be started automatically for you.
If you are using any subsystems other than the IBM-supplied subsystems, you might also need to start these subsystems before you start TCP/IP.
See the server table to understand how the servers map to the actual jobs and subsystems they represent.