Enabling Loopback Test; Link Aggregation - 3Com 4200G 12-Port Configuration Manual

To do...
Enter system view
Enable loopback detection
globally
Set the interval for performing
port loopback detection
Enter Ethernet port view
Enable loopback port control on
the trunk or hybrid port
Configure the system to run
loopback detection on all
VLANs of the current trunk or
hybrid port
Enable loopback detection on a
specified port
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.
After you use the undo loopback-detection enable command in system view, loopback detection
will be disabled on all ports.
The commands of loopback detection feature cannot be configured with the commands of port link
aggregation at the same time.
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:
Use the command...
system-view
loopback-detection enable
loopback-detection
interval-time time
interface interface-type
interface-number
loopback-detection control
enable
loopback-detection per-vlan
enable
loopback-detection enable
1-5
Remarks
—
Required
By default, loopback detection
is disabled globally.
Optional
The default is 30 seconds.
—
Optional
By default, loopback port
control is not enabled.
Optional
By default, the system runs
loopback detection only on the
default VLAN of the current
trunk or hybrid port.
Required
By default, port loopback
detection is disabled.