H3C Technologies H3C S12500-X Series Switches - Manual (Page 119)

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[DeviceC-Ten-GigabitEthernet1/0/1] port trunk permit vlan 100
[DeviceC-Ten-GigabitEthernet1/0/1] quit
[DeviceC] interface ten-gigabitethernet 1/0/2
[DeviceC-Ten-GigabitEthernet1/0/2] port link-type trunk
[DeviceC-Ten-GigabitEthernet1/0/2] port trunk permit vlan 100
[DeviceC-Ten-GigabitEthernet1/0/2] quit
Verifying the configuration
After the configurations are complete, Device A detects loops on ports Ten-GigabitEthernet 1/0/1
and Ten-GigabitEthernet 1/0/2 within a loop detection interval. Consequently, Device A
automatically shuts down the ports and generates the following log messages:
[DeviceA]
%Feb 24 15:04:29:663 2011 DeviceA LPDT/4/LOOPED:Slot=1;
Loopback exists on Ten-GigabitEthernet1/0/1.
%Feb 24 15:04:29:667 2011 DeviceA LPDT/4/LOOPED:Slot=1;
Loopback exists on Ten-GigabitEthernet1/0/2.
%Feb 24 15:04:44:243 2011 DeviceA LPDT/4/RECOVERED:Slot=1;
Loopback on Ten-GigabitEthernet1/0/1 recovered.
%Feb 24 15:04:44:248 2011 DeviceA LPDT/4/RECOVERED:Slot=1;
Loopback on Ten-GigabitEthernet1/0/2 recovered.
Use the display loopback-detection command to display the loop detection configuration and
status on Device A.
# Display the loop detection configuration and status on Device A.
[DeviceA] display loopback-detection
Loop detection is enabled.
Loop detection interval is 35 second(s).
No loopback is detected.
The output shows that the device has removed the loops from Ten-GigabitEthernet 1/0/1 and
Ten-GigabitEthernet 1/0/2 according to the shutdown action. Use the display interface command
to display the status of Ten-GigabitEthernet 1/0/1 and Ten-GigabitEthernet 1/0/2 on Device A.
# Display the status of Ten-GigabitEthernet 1/0/1 on Device A.
[DeviceA] display interface ten-gigabitethernet 1/0/1
Ten-GigabitEthernet1/0/1 current state: DOWN (Loop detection down)
...
# Display the status of Ten-GigabitEthernet 1/0/2 on Device A.
[DeviceA] display interface ten-gigabitethernet 1/0/2
Ten-GigabitEthernet1/0/2 current state: DOWN (Loop detection down)
...
The output shows that Ten-GigabitEthernet 1/0/1 and Ten-GigabitEthernet 1/0/2 are already
shut down by the loop detection module.