When Netmaster for TCPIP is started for the first time, the Express Setup for the region runs to discover the network which should be controlled by the Netmaster for TCPIP.
If you want to run that Express Setup again you can do that in Menu /RADMIN.AD.I (or =A.R.AD.I) and start the Process with PF6. The discovered resources are placed in a newly created System Image. You can directly use this new System Image as the active one. You can influence the amount of discovered Resources by updating a copy of the Control Member. The default for this member is $RMEXPR6 and is located in 'hlq.CC2DEXEC'.