PLANET WGSW-50040 - Manual (Page 106)

Chapter 4 Commands for
Port Loopback Detection
Function
4.1 loopback-detection control
Command:
loopback-detection control {shutdown |block| learning}
no loopback-detection control
Function:
Enable the function of loopback detection control on a port, the no operation of this command will
disable the function.
Parameters:
shutdown set the control method as shutdown, which means to close down the port if a port
loopback is found.
block set the control method as block, which means to block a port by allowing bpdu and loopback
detection messages only if a port loopback is found.
learning disable the control method of learning MAC addresses on the port, not forwarding traffic
and delete the MAC address of the port.
Default:
Disable the function of loopback diction control.
Command Mode:
Port Mode.
Usage Guide:
If there is any loopback, the port will not recovery the state of be controlled after enabling control
operation on the port. If the overtime is configured, the ports will recovery normal state when the
overtime is time-out. If the control method is block, the corresponding relationship between instance
and vlan id should be set manually by users, it should be noticed when be used.
Example:
Enable the function of loopback detection control under port1/2 mode.
Switch(config)#interface ethernet 1/2
Switch(Config-If-Ethernet1/2)#loopback-detection control shutdown
Switch(Config-If-Ethernet1/2)#no loopback-detection control