Jan 26

What is loopback Detection The Loopback Detection function is used to detect the loop created by a specific port while Spanning Tree Protocol (STP) is not enabled in the network, especially when the down link devices are hubs or unmanaged switches. The Switch will automatically shut down the port and sends a log to the administrator. The Loopback Detection port will be unlocked when the Loopback Detection Recover Time times out. The Loopback Detection function can be implemented on a range of ports at a time.


Step 1: Open an Internet browser (such as Internet Explorer) and enter (if the switch has the default IP address) in the address bar,  then press Enter.

NOTE: If you have changed the IP address, plesae use the assigned IP address instead of the default.



Step 2: Enter the password for your Admin account in the field provided. If you have not changed this password from the default, the password is ”admin”. Click OK.



Step 3: Click L2 Functions then select Loopback Detection.



Step 4: Under Loopback Detection Settings

  • Enable Loopback detection.
  • Select the mode, specify Port-based or VLAN-based mode.
  • Set a Loop detection Interval between 1 and 32767 seconds. The default is 2 seconds. Click Apply to save your changes.



  • From Port: The beginning of a consecutive group of ports may be configured starting with the selected port.
  • To Port: The ending of a consecutive group of ports may be configured starting with the selected port.
  • State: Use the drop-down menu to toggle between Enabled and Disabled. The default is disabled. Click Apply to implement changes made or click Refresh to refresh the Loopback Detection table.


Step 5: Save the configuration. Click the Save tab, select Save Configuration, then click Save Config.




You have successfully enabled the loopback detection for the DGS-1500 switch.

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