NEC INTELLIGENT L2 SWITCH N8406-022A - Manual (Page 58)

RSTP and MSTP 58
b. Open the MSTP/RSTP folder, and select General.
c. Select RSTP mode, and set the MSTP/RSTP state to ON.
d. Click Submit.
3. Apply, verify, and save the configuration.
Open
Select
1. Apply
3. Save
2. Verify