10
Hardware Loopback test compatibility
F5020/F5040 Yes
M9006/M9010/M9014 Yes
VFW1000 No
If an Ethernet interface does not work correctly, you can perform a loopback test on it to identify the
problem. An Ethernet interface in a loopback test does not forward data traffic.
Loopback tests include the following types:
•
Internal loopback test
—Tests all on-chip functions associated with the Ethernet interface.
•
External loopback test
—Tests the hardware of the Ethernet interface. To perform an external
loopback test on the Ethernet interface, connect a loopback plug to the Ethernet interface. The
device sends test packets out of the Ethernet interface, which are expected to loop over the plug and
back to the Ethernet interface. If the Ethernet interface fails to receive any test packets, the hardware
of the Ethernet interface is faulty.
Configuration restrictions and guidelines
When you perform loopback tests, follow these restrictions and guidelines:
•
On an administratively shut down Ethernet interface (displayed as in
ADM
or
Administratively
DOWN
state), you cannot perform an internal or external loopback test.
•
During a loopback test on an Ethernet interface, the
speed
,
duplex
,
mdix-mode
, and
shutdown
commands are not available on the Ethernet interface.
•
During a loopback test on an Ethernet interface, the Ethernet interface operates in full duplex mode.
When the loopback test is complete, the Ethernet interface restores to its duplex setting.
Configuration procedure
To perform a loopback test on an Ethernet interface:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter Ethernet interface view.
interface
interface-type
interface-number
N/A
3.
Perform a loopback test.
loopback
{
external
|
internal
}
By default, no loopback test is
performed on the Ethernet
interface.
Configuring generic flow control on an Ethernet interface
The following matrix shows the feature and hardware compatibility:
Hardware
Generic flow control compatibility
F5020/F5040 Yes
M9006/M9010/M9014 Yes
VFW1000 No
