The Port Cable Test feature enables you to determine the cable connection status on a selected port. You can also obtain an estimate of the length of the cable connected to the port, if the PHY (Physical Interface Transceiver) on the ports supports this functionality.
Note
The cable test feature is supported only for copper cable. It is not supported for optical fiber cable.To access this page, click
.The page displays with additional fields when you click Test Cable. The fields that display depend on the cable test results.
Field | Description |
---|---|
Interface | If the test has not been performed, this is the only field that displays. Select the interface to test. After the test has been performed, this field shows the interface that was tested. |
Cable Status | This displays the cable status as Normal, Open, or Short.
|
Cable Length | The estimated length of the cable. If the cable length
cannot be determined, Unknown is displayed. This field shows the range between
the shortest estimated length and the longest estimated length. Note: This field
displays a value only when the Cable Status is Normal; otherwise, this field
is blank.
|
Failure Location | The estimated distance from the end of the cable to the
failure location. Note: This field displays a value only when the Cable Status
is Open or Short; otherwise, this field is blank.
|
Select a port and click Test Cable to display its status.
If the port has an active link while the cable test is run, the link can go down for the duration of the test. The test may take several seconds to run.
The command returns a cable length estimate if this feature is supported by the PHY for the current link speed. Note that if the link is down and a cable is attached to a 10/100 Ethernet adapter, then the cable status may display as Open or Short because some Ethernet adapters leave unused wire pairs unterminated or grounded.