PLANET XGS3-24040 - Manual (Page 92)

Chapter 9 Port Loopback Dection Function Configuration
9-6
If adopting the control method of block, MSTP should be globally enabled. And the correspondence between
the spanning tree instance and the VLAN should be configured.
Switch(config)#spanning-tree
Switch(config)#spanning-tree mst configuration
Switch(Config-Mstp-Region)#instance 1 vlan 1
Switch(Config-Mstp-Region)#instance 2 vlan 2
Switch(Config-Mstp-Region)#
9.4 Port Loopback Detection Troubleshooting
The function of port loopback detection is disabled by default and should only be enabled if required.