GE Multilink ML810 Instruction Manual page 230

CONFIGURING STP/RSTP WITH ENERVISTA SECURE WEB MANAGEMENT SOFTWARE CHAPTER 13: RAPID SPANNING TREE PROTOCOL
Note
13–22
Only 2 ports can be selected to Ring Only Mode.
 Select the Enabled option for the Status setting as shown below:
 Save the configuration by clicking on the
MULTILINK ML810 MANAGED EDGE SWITCH – INSTRUCTION MANUAL
icon.