H3C Technologies H3C SecPath F1000-E - Manual (Page 5)

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To do… Use the command… Remarks
Change the description of the
subinterface
description text
Optional
By default, the description string is
“interface index + Interface”. For example,
GigabitEthernet0/1.1 Interface.
Shut down the Ethernet
subinterface
shutdown
Optional
By default, an Ethernet subinterface is in up
state.
NOTE:
•
You can perform IP-related configuration for an Ethernet subinterface. For more information, see the IP
Services Volume.
• For the local and remote Ethernet subinterfaces to transmit traffic correctly, configure them with the same
subinterface number and VLAN ID.
Configuring Loopback Testing on an Ethernet Interface
If an Ethernet interface does not work normally, you can enable loopback testing on it to identify the
problem. There are two types of loopback testing:
• Internal loopback testing, which tests all on-chip functions related to Ethernet interfaces.
• External loopback testing, which tests the hardware of Ethernet interfaces. To perform external
loopback testing on an Ethernet interface, connect a loopback plug to the Ethernet interface. The
device sends test packets out the interface, which are expected to loop over the plug and back to
the interface. If the interface fails to receive any test packet, the hardware of the interface is faulty.
An Ethernet interface in a loopback test does not forward data traffic.
Follow these steps to enable loopback testing on an Ethernet interface:
To do… Use the command… Remarks
Enter system view system-view —
Enter Ethernet interface view
interface interface-type
interface-number
—
Enable loopback testing
loopback { external |
internal } Optional
Disabled by default.
NOTE:
•
On an interface that is physically down, you can perform only internal loopback testing. On an interface
administratively shut down, you can perform neither internal nor external loopback testing.
• The speed, duplex, mdi, and shutdown commands are unavailable during loopback testing.
• During loopback testing, an Ethernet interface works in full duplex mode. When you disable loopback
testing, the duplex configuration of the interface restores.