JetStream  52-Port Gigabit Stackable L3 Managed Switch  CLI Guide 
 
Syntax 
loopback-detection   
no loopback-detection 
Command Mode 
Interface Configuration Mode (interface fastEthernet / interface range 
fastEthernet / interface gigabitEthernet / interface range gigabitEthernet / 
interface ten-gigabitEthernet / interface range ten-gigabitEthernet / interface 
port-channel) 
Example 
Enable the loopback detection function of ports 1-3: 
T3700G-52TQ(config)# interface range gigabitEthernet 1/0/1-3 
T3700G-52TQ(config-if-range)# loopback-detection 
28.5  loopback-detection config 
Description 
The  loopback-detection config  command is used to configure the 
process-mode and recovery-mode for the ports or LAGs by which the switch 
copes with the detected loops. 
Syntax 
loopback-detection config  process-mode  { alert | port-based } 
recovery-mode { auto | manual } 
Parameter 
alert | port-based  ——  The mode how the switch processes the detected 
loops.  Alert:  When a loop is detected, display an alert. Port based: When a 
loop is detected, display an alert and block the port. 
auto | manual —— The mode how the blocked port recovers to normal status. 
Auto: Block status can be automatically removed after recovery time. Manual: 
Block status can only be removed manually. 
Command Mode 
Interface Configuration Mode (interface fastEthernet / interface range 
fastEthernet / interface gigabitEthernet / interface range gigabitEthernet / 
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