HP HSR6800 Configuration Manual page 18

To enable a hybrid or trunk port to take the administratively specified protective action, you must use
•
the loopback-detection control enable command on the port.
When you change the link type of an Ethernet interface by using the port link-type command, the
•
switch removes the protective action configured on the interface. For more information about the
port link-type command, see Layer 2—LAN Switching Command Reference.
Configuration procedure
To configure loopback detection:
Step
1. Enter system view.
2. Enable global loopback
detection.
3. Enable multi-port loopback
detection.
4. Set the loopback detection
interval.
5. Enter Ethernet interface view
or port group view.
Enable loopback detection on
6.
the interface.
7. Enable loopback detection
control on a trunk port or a
hybrid port.
8. Enable loopback detection in
all VLANs on the trunk or
hybrid port.
9. Set the protective action to
take on the interface when a
loop is detected.
Command
system-view
loopback-detection enable
loopback-detection
multi-port-mode enable
loopback-detection interval-time
time
•
Enter Ethernet interface view:
interface interface-type
interface-number
•
Enter port group view:
port-group manual
port-group-name
loopback-detection enable
loopback-detection control enable
loopback-detection per-vlan
enable
loopback-detection action
{ no-learning | semi-block |
shutdown }
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Remarks
N/A
By default, global loopback
detection is disabled.
Optional.
By default, multi-port loopback
detection is disabled, and the
router can detect only single-port
loops.
Optional.
The default setting is 30 seconds.
Use one of the commands.
To configure loopback detection
on one interface, enter Ethernet
interface view.
To configure loopback detection
on a group of Ethernet interfaces,
enter port group view.
By default, loopback detection is
disabled.
Optional.
By default, loopback detection
control is disabled.
Optional.
By default, a trunk or hybrid port
performs loopback detection only
in its PVID.
Optional.
By default, when a loop is detected
on an interface, the interface does
not forward any data packet.
With the shutdown keyword
specified, the looped port is
automatically shut down and its
physical state changes to Loop
down. After the loop is removed,
use the undo shutdown command
on the port to recover its
forwarding capability.