Loopback-Detection Control Enable - H3C S7500E Series Command Reference Manual

Parameters
no-learning: Disables MAC address learning on the interface.
semi-block: Blocks all packets but STP BPDUs.
shutdown: Shuts down the Ethernet interface. To bring up the interface again, use the undo
shutdown command.
Description
Use the loopback-detection action command to configure the action for loop protection on Ethernet
interfaces.
Use the undo loopback-detection action command to restore the default.
By default, a looped interface discards all incoming packets but still forwards outgoing packets; the
system generates traps and deletes all MAC address entries of the looped interface.
After you change the link type of an Ethernet interface by using port link-type command, the device
removes the protective action configured on the interface. For more information about the port
link-type command, see VLAN Configuration Commands in the Layer 2 – LAN Switching Command
Reference.
Configure Ethernet interfaces one by one in Ethernet interface view or in bulk in port group view.
Examples
# Configure access port GigabitEthernet 2/0/1 to shut down when a loop is detected.
<Sysname> system-view
[Sysname] loopback-detection enable
[Sysname] interface GigabitEthernet 2/0/1
[Sysname-GigabitEthernet2/0/1] loopback-detection enable
[Sysname-GigabitEthernet2/0/1] loopback-detection action shutdown
# Configure trunk port GigabitEthernet 2/0/2 to shut down when a loop is detected.
<Sysname> system-view
[Sysname] loopback-detection enable
[Sysname] interface gigabitEthernet 2/0/2
[Sysname-GigabitEthernet2/0/2] port link-type trunk
[Sysname-GigabitEthernet2/0/2] loopback-detection enable
[Sysname-GigabitEthernet2/0/2] loopback-detection control enable
[Sysname-GigabitEthernet2/0/2] loopback-detection action shutdown

loopback-detection control enable

Syntax
loopback-detection control enable
undo loopback-detection control enable
View
Ethernet interface view, port group view
Default Level
2: System level
Parameters
None
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