Configuring The Mdi Mode For An Ethernet Interface - HP 4800G Series Configuration Manual

To do...
Enter system view
Enable global loopback
detection
Configure the interval for port
loopback detection
Enter Ethernet interface view
Enable loopback detection on a
port
Enable loopback detection
control on a trunk port or a
hybrid port
Enable loopback detection in all
the VLANs to which trunk or
hybrid ports belong
Loopback detection on a given port is enabled only after the loopback-detection enable
command has been configured in both system view and the interface view of the port.
Loopback detection on all ports will be disabled after the configuration of the undo
loopback-detection enable command under system view.

Configuring the MDI Mode for an Ethernet Interface

10-Gigabit Ethernet ports and optical interfaces of SFP ports do not support this function.
Two types of Ethernet cables can be used to connect Ethernet devices: crossover cable and
straight-through cable. To accommodate these two types of cables, an Ethernet interface on a device
can operate in one of the following three Medium Dependent Interface (MDI) modes:
Across mode
Normal mode
Auto mode
An Ethernet interface is composed of eight pins. By default, each pin has its particular role. For example,
pin 1 and pin 2 are used for transmitting signals; pin 3 and pin 6 are used for receiving signals. You can
change the pin roles through setting the MDI mode. For an Ethernet interface in normal mode, the pin
roles are not changed. For an Ethernet interface in across mode, pin 1 and pin 2 are used for receiving
Use the command...
system-view
loopback-detection enable
loopback-detection
interval-time time
interface interface-type
interface-number
loopback-detection enable
loopback-detection control
enable
loopback-detection per-vlan
enable
1-8
Remarks
—
Required
Disabled by default
Optional
30 seconds by default
—
Required
Disabled by default
Optional
Disabled by default
Optional
Enabled only in the default
VLAN(s) with trunk port or
hybrid ports