run diagnostics cable ports

run diagnostics cable ports [port_list | all]

Description

Runs cable diagnostics on one or more copper ports using Time Domain Reflectometry (TDR) technology embedded in the PHY chips. This command helps identify physical issues in twisted pair cabling such as breaks, shorts, or interference.

Syntax Description


`port_list`	Specifies to run diagnostics on a given port or set of ports.
all	Specifies to run diagnostics on all active ports.

Default

N/A.

Usage Guidelines

Diagnostics are supported only on copper ports.
Not supported on extended BPE ports, stacking ports, or fiber ports.
Running diagnostics may momentarily interfere with traffic on active ports.
Results are reported per twisted pair (typically four pairs per port).


State	Meaning
`Ok`	No fault detected; pair is functioning normally.
`Open`	Pair is not terminated or has a physical break. May be expected if unplugged.
`Short`	Conductors are shorted together.
`Crosstalk`	Interference detected between pairs; may indicate poor shielding or cable quality.
`Unknown`	Diagnostic failed or result is inconclusive.

Note

An Open state may be expected if the cable is not connected at the far end. If the cable is expected to be connected, this may indicate a fault.

Gigabit Ethernet (1000BASE-T): All four pairs should report Ok.
Fast Ethernet (100BASE-TX): Only pairs A and B are used; pairs C and D may show Open and still be valid.

Example

The following example runs diagnostics on port 14:

 # run diagnostics cable ports 14
Do you want to continue cable diagnostics? (y/N) Yes
cablediag: 1.1.0.14


+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+                             C A U T I O N                             +
+   cablediag will momentarily interfere with traffic on active ports   +
+-----------------------------------------------------------------------+
+   Ports: 14                                                           +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Collecting port cable diagnostic information may take a moment...
port 14: cable (4 pairs, length +/- 10 meters)
        pair A Ok, length 0 meters
        pair B Ok, length 0 meters
        pair C Ok, length 4 meters
        pair D Ok, length 4 meters

Example with Faults

The following example runs diagnostics on port 3, which returns faults:

port 3: cable (4 pairs, length +/- 10 meters)
pair A Ok, length 5 meters
pair B Open, length 7 meters
pair C Crosstalk, length 6 meters
pair D Ok, length 5 meters

History

This command was first available in ExtremeXOS 22.5.

Platform Availability

This command is available on all platforms supporting copper ports.