H3C Technologies H3C WX5500E Series Access Controllers - Manual (Page 22)

11
Step Command Remarks
5. Enter Ethernet interface view
or port group view.
• Enter Ethernet interface view:
interface interface-type
interface-number
• Enter port group view:
port-group manual
port-group-name
Use one of the commands.
To configure loopback detection
on one interface, enter Ethernet
interface view.
To configure loopback detection
on a group of Ethernet interfaces,
enter port group view.
6. Enable loopback detection on
the interface.
loopback-detection enable
By default, loopback detection is
disabled.
7. Enable loopback detection
control on a trunk port or a
hybrid port.
loopback-detection control enable
Optional.
By default, loopback detection
control is disabled.
8. Enable loopback detection in
all the VLANs on the trunk or
hybrid port.
loopback-detection per-vlan
enable
Optional.
By default, a trunk or hybrid port
performs loopback detection only
in its PVID.
9. Set the protective action to
take on the interface when a
loop is detected.
loopback-detection action
{ no-learning | semi-block |
shutdown }
Optional.
By default, when a loop is detected
on an interface, the interface does
not receive or send packets, and
the system generates traps and log
messages and deletes all MAC
address entries of the interface.
With the shutdown keyword
specified, the looped port is
automatically shut down and its
physical state changes to Loop
down. After the loop is removed,
use the undo shutdown command
on the port to recover its
forwarding capability.
Setting the MDI mode of an Ethernet interface
IMPORTANT:
Fiber ports do not support the MDI mode setting.
You can use both crossover and straight-through Ethernet cables to connect copper Ethernet interfaces.
To accommodate these types of cables, a copper Ethernet interface can operate in one of the following
Medium Dependent Interface (MDI) modes:
• Across mode
• Normal mode
• Auto mode
A copper Ethernet interface uses an RJ-45 connector, which comprises eight pins, each of which plays a
dedicated role. For example, pins 1 and 2 transmit signals, and pins 3 and 6 receive signals. The pin
role varies by the MDI modes as follows: