Operation Manual – Port Basic Configuration
H3C S3100 Series Ethernet Switches
Chapter 1 Port Basic Configuration
1-7
1.1.7 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.
Table 1-6
Enable loopback test
Operation
Command
Remarks
Enter system view
system-view
—
Enter Ethernet port view
interface interface-type
interface-number
—
Enable loopback test
loopback
{
external
|
internal
}
Optional
Note:
z
external:
Performs external loop test. In the external loop test, self-loop headers
must be used on the port of the switch ( for 100M port, the self-loop headers are
made from four cores of the 8-core cables, for 1000M port, the self-loop header are
made from eight cores of the 8-core cables, then the packets forwarded by the port
will be received by itself.). The external loop test can locate the hardware failures on
the port.
z
internal
: Performs internal loop test. In the internal loop test, self loop is established
in the switching chip to locate the chip failure which is related to the port.
Note that:
z
After you use the
shutdown
command on a port, the port cannot run loopback
test.
z
You cannot use the
speed
,
duplex
,
mdi
and
shutdown
commands on the ports
running loopback test.
z
Some ports do not support loopback test, and corresponding prompts will be given
when you perform loopback test on them.
1.1.8 Configuring a Port Group
To make the configuration task easier for users, certain devices allow users to configure
on a single port as well as on multiple ports in a port group. In port group view, the user
only needs to input the configuration command once on one port and that configuration
will apply to all ports in the port group. This effectively reduces redundant
configurations.
A Port group could be manually created by users. Multiple Ethernet ports can be added
to the same port group but one Ethernet port can only be added to one port group.
