show cable-diagnostics tdr
User EXEC mode
VCT technology enables the diagnosis of a wire or cable conductor by sending a pulsed signal into the conductor and examining the reflection of that pulse. This method of cable analysis is referred to as TDR. By examining the reflection, the ICX device can detect and report cable data, such as line speed, cable length, and link pair status.
If the VCT TDR test results show that the Pair Status is not terminated, further investigation and likely cable replacement is required. Alternatively, connectivity issues at the end of a RJ-45 cable connector may have occurred.
For more information on analyzing TDR test results, refer to the Viewing the Results of the Cable Analysis section of the RUCKUS FastIron Monitoring Configuration Guide.
The show cable-diagnostics
tdr command output displays the following information:
The following example shows the VCT TDR test results for port 1/1/48 for an ICX 8200-48ZP2 device. The results indicate that the port is down or the cables are not connected. The port speed is unknown, with each pair having a potential fault less than or equal to three meters away from the testing point, and all pairs showing an open status.
ICX8200-48ZP2> show cable-diagnostics tdr 1/1/48
Port Speed Local pair Pair Length Remote pair Pair status
---- ----- ---------- ----------- ----------- -----------
1/1/48 UKNWN Pair A <=3M open
Pair B <=3M open
Pair C <=3M open
Pair D <=3M open
The following example shows the VCT TDR test results for port 1/1/33 for an ICX 8200-48ZP2 device. The results indicate that the port is operating at 2.5G speed, with all pairs terminated and having no faults (Pair Length = NA).
ICX8200-48ZP2> show cable-diagnostics tdr 1/1/33
Port Speed Local pair Pair Length Remote pair Pair status
---- ----- ---------- ----------- ----------- -----------
1/1/33 2.5G Pair A NA Pair B terminated
Pair B NA Pair A terminated
Pair C NA Pair D terminated
Pair D NA Pair C terminated
The following output displays the VCT TDR test results for port 1/1/48 on an ICX 8200-48ZP2 device. The results indicate that the speed is unknown, with pairs A, C, and D terminated. Pair B shows an open status, indicating a potential fault less than or equal to three meters from the testing point.
ICX8200-48ZP2> show cable-diagnostics tdr 1/1/48
Port Speed Local pair Pair Length Remote pair Pair status
---- ----- ---------- ----------- ----------- -----------
1/1/48 UKNWN Pair A NA Pair B terminated
Pair B <=3M open
Pair C NA Pair D terminated
Pair D NA Pair C terminated
The following example shows the VCT TDR test results for port 1/1/47 for an ICX 8200-48ZP2 device. The results indicate that the port speed is unknown, with potential faults detected at less than or equal to eleven meters from the testing point for each pair, all of which are experiencing short circuits within the same pair.
ICX8200-48ZP2> show cable-diagnostics tdr 1/1/47
Port Speed Local pair Pair Length Remote pair Pair status
---- ----- ---------- ----------- ----------- -----------
1/1/47 UKNWN Pair A <=11M samepairshort
Pair B <=11M samepairshort
Pair C <=11M samepairshort
Pair D <=11M samepairshort
The following example shows the VCT TDR test results for port 1/1/47 on an ICX 8200-48ZP2 device. The results indicate that the port speed is unknown, with Pair A, Pair B, and Pair C experiencing short circuits within the same pair at distances less than or equal to eleven meters from the testing point. Pair D shows an open status, indicating a potential fault less than or equal to twelve meters from the testing point.
ICX8200-48ZP2> show cable-diagnostics tdr 1/1/47
Port Speed Local pair Pair Length Remote pair Pair status
---- ----- ---------- ----------- ----------- -----------
1/1/47 UKNWN Pair A <=11M samepairshort
Pair B <=11M samepairshort
Pair C <=11M samepairshort
Pair D <=12M open
The following output illustrates the VCT TDR test results for port 1/1/48 on an ICX 8200-48ZP2 device. The results indicate that the port speed is unknown, with pairs A and B each showing a 'crosspairshort' fault, indicating a short circuit between different pairs of wires within 3 meters from the testing point. Pairs C and D are terminated.
ICX8200-48ZP2> show cable-diagnostics tdr 1/1/48
Port Speed Local pair Pair Length Remote pair Pair status
---- ----- ---------- ----------- ----------- -----------
1/1/48 UKNWN Pair A <=3M crosspairshort
Pair B <=3M crosspairshort
Pair C NA Pair D terminated
Pair D NA Pair C terminated