Interfaces can be stopped by selecting the realm node where the interface you want to stopped is running, and selecting the Interfaces tab. From the table of configured interfaces, select the interface you want to stop and double-click on the row. Alternatively, you can click on the Status column for the interface. Both will have the same effect, and will present you with a dialog for stopping the selected interface.

Clicking on the Stop button will stop the interface on the realm server.