Setting The Mdi Mode Of An Ethernet Interface - H3C S5500-EI Series Configuration Manual

receives packets sent out Port 2, a multi-port loop occurs between the two interfaces, and Port 1 (the
interface that receives the looped packets) is the looped interface. Multi-port loops may also cause
broadcast storms.
Figure 5 Network diagram for multi-port loopback detection
Switch A
Port 1
Loop
LAN
The multi-port loopback detection function detects loops among interfaces on your switch. You can use
the loopback-detection action command to configure the protective action to take on looped interfaces,
for example, to shut down the interface, eliminating the loops. In addition, the switch also takes other link
type-dependant actions on the looped interface (for example, Port 1 in
of the loop condition. For more information, see
interface."
Multi-port loopback detection is implemented on the basis of single-port loopback detection
configurations on Ethernet interfaces. To implement multi-port loopback detection, you must enable
single-port loopback detection on one or multiple Ethernet interfaces on the switch.
Follow these steps to configure multi-port loopback detection:
To do...
Enter system view
Enable multi-port loopback
detection
NOTE:
To enable multi-port loopback detection, you must configure the loopback-detection multi-port-mode
•
enable and loopback-detection enable commands in system view, and configure the
loopback-detection enable command in the view of the related interfaces.
• The single-port loopback detection function is available when the switch is performing multi-port
loopback detection.

Setting the MDI mode of an Ethernet interface

NOTE:
Optical interfaces 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 two types of cables, a copper Ethernet interface can operate in one of the
following Medium Dependent Interface (MDI) modes:
Across mode
•
Port 2
Use the command...
system-view
loopback-detection
multi-port-mode enable
"Enabling single-port loopback detection on an Ethernet
15
5) to alleviate the impact
Figure
Remarks
—
Required
Disabled by default.