Operation
Command
Remarks
Enable loopback port
control on the trunk or
hybrid port
loopback-detection control
enable
Optional
By default, the loopback port control
function is enabled on ports if the
device boots with the default
configuration file (config.def); if the
device boots with null configuration,
this function is disabled.
Enable the loopback port
auto-shutdown function
loopback-detection
shutdown enable
Optional
By default, the loopback port
auto-shutdown function is enabled on
ports if the device boots with the default
configuration file (config.def); if the
device boots with null configuration,
this function is disabled.
Configure the system to
run loopback detection
on all VLANs of the
current trunk or hybrid
port
loopback-detection
per-vlan enable
Optional
By default, the system runs loopback
detection only on the default VLAN of
the current trunk or hybrid port.
z
To enable loopback detection on a specific port, you must use the
loopback-detection enable
command in both system view and the specific port view.
z
After you use the
undo loopback-detection enable
command in system view, loopback detection
will be disabled on all ports.
z
The
loopback-detection control enable
command
and the
loopback-detection per-vlan
enable
command are not applicable to access ports. When the link type of a non-access port
changes to access, the two commands already configured on the port become invalid
automatically.
Enabling Loopback Test
You can configure the Ethernet port to run loopback test to check if it operates normally. The port
running loopback test cannot forward data packets normally. The loopback test terminates
automatically after a specific period.
Follow these steps to enable loopback test:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter Ethernet port view
interface interface-type interface-number
—
Enable loopback test
loopback
{
external
|
internal
}
Required
12-7
