Grandstream Networks GHP6 Series Administration Manual page 37

Zero Configuration settings
Click "Pick Extension Segment" to switch to the menu "PBX Settings" – "General Settings", and enter the corresponding
number segment value. Make sure to click save afterward to save the changes.
Picking Extension Segments
The UCM6301 automatically discovers and manages device addresses on the same network segment. At the same time,
UCM supports manual input of device IP to discover devices.
Zero Config main page