Testing The Cable On An Ethernet Interface - H3C LS-3100-52P-OVS-H3 Operation Manual

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
signals; pin 3 and pin 6 are used for transmitting signals. To enable normal communication, you should
connect the local transmit pins to the remote receive pins. Therefore, you should configure the MDI
mode depending on the cable types.
Normally, the auto mode is recommended. The other two modes are useful only when the device
cannot determine the cable type.
When straight-through cables are used, the local MDI mode must be different from the remote MDI
mode.
When crossover cables are used, the local MDI mode must be the same as the remote MDI mode,
or the MDI mode of at least one end must be set to auto.
Follow these steps to configure the MDI mode for an Ethernet interface:
To do...
Enter system view
Enter Ethernet interface view
Configure the MDI mode for the
Ethernet interface

Testing the Cable on an Ethernet Interface

10-Gigabit Ethernet ports and Combo ports operating as optical interfaces do not support this
feature.
A link in the up state goes down and then up automatically if you perform the operation described in
this section on one of the Ethernet interfaces forming the link.
Follow these steps to test the current operating state of the cable connected to an Ethernet interface:
To do...
Enter system view
Enter Ethernet interface view
Test the cable connected to the
Ethernet interface once
Use the command...
system-view
interface interface-type
interface-number
mdi { across | auto | normal }
Use the command...
system-view
interface interface-type
interface-number
virtual-cable-test
1-8
Remarks
—
—
Optional
Defaults to auto. That is, the
Ethernet interface determines
the physical pin roles (transmit
or receive) through negotiation.
Remarks
—
—
Required