Loopback Detection Settings - D-Link DES-3528 - xStack Switch - Stackable Reference Manual

xStack® DES-3528/DES-3552 Series Layer 2 Stackable Fast Ethernet Managed Switch Web UI Reference Guide

Loopback Detection Settings

The Loopback Detection (LBD) function is used to detect the loop created by a specific port. This feature is used to
temporarily shut down a port on the Switch when a CTP (Configuration Testing Protocol) packet has been looped back
to the Switch. When the Switch detects CTP packets received from a port or a VLAN, this signifies a loop on the
network. The Switch will automatically block the port or the VLAN and send an alert to the administrator. The Loopback
Detection port will restart (change to discarding state) when the Loopback Detection Recover Time times out. The
Loopback Detection function can be implemented on a range of ports at a time. The user may enable or disable this
function using the pull-down menu.
To view this window, click Security > Loopback Detection Settings, as shown below:
The fields that can be configured are described below:
Parameter
Loopback Detection
State
Mode
Interval (1-32767)
Trap Status
Recover Time (0 or 60-
1000000)
Log State
Figure 8-55 Loopback Detection Settings window
Description
Use the radio button to enable or disable loopback detection. The default is Disabled.
Use the drop-down menu to toggle between Port-based and VLAN-based.
The time interval (in seconds) that the device will transmit all the CTP (Configuration
Test Protocol) packets to detect a loop-back event. The valid range is from 1 to 32767
seconds. The default setting is 10 seconds.
Set the desired trap status: None, Loop Detected, Loop Cleared, or Both.
Time allowed (in seconds) for recovery when a Loopback is not detected. The Loop-
detect Recover Time can be set at 0 seconds, or 60 to 1000000 seconds. Entering 0
will disable the Loop-detect Recover Time. The default is 60 seconds.
Use the drop-down menu to enable or disable the log state.
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