Loopback Detection Settings - D-Link xStack Reference Manual

®
xStack DGS-3200 Series Layer 2 Managed Gigabit Ethernet Switch Web UI Reference Guide
Log State
Recover Time (60-
1000000)
From Port / To Port
State
Mode
Click Apply to implement the changes made.

Loopback Detection Settings

The Loopback Detection function is used to detect the loop created by a specific port. This feature is used to temporarily
shutdown 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 drop-down menu.
To view the following window, click Security > Loopback Detection Settings:
Specify when a log entry will be sent. Options to choose from are None, Attack Detected,
Attack Cleared or Both.
Enter the BPDU protection Auto-Recovery timer. The default value of the recovery timer is
60. Tick the Infinite check box for not auto recovering.
Use the drop-down menus to select t a range of ports.
Use the drop-down menu to enable or disable the protection mode for a specific port.
Specify the BPDU protection mode. The default mode is shutdown.
Drop – Drop all received BPDU packets when the port enters under attack state.
Block – Drop all packets (include BPDU and normal packets) when the port enters under
attack state.
Shutdown – Shut down the port when the port enters under attack state.
Figure 6 - 79. Loopback Detection Settings window
195