Using tdr, Understanding tdr – Dell POWEREDGE M1000E User Manual

Page 1187

Advertising
background image

47-15

Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide

OL-13270-03

Chapter 47 Troubleshooting

Using TDR

4 171.9.4.5 0 msec 4 msec 0 msec

5 171.9.121.34 0 msec 4 msec 4 msec

6 171.9.15.9 120 msec 132 msec 128 msec

7 171.9.15.10 132 msec 128 msec 128 msec

Switch#

The display shows the hop count, the IP address of the router, and the round-trip time in milliseconds
for each of the three probes that are sent.

To end a trace in progress, enter the escape sequence (Ctrl-^ X by default). Simultaneously press and
release the Ctrl, Shift, and 6 keys and then press the X key.

Using TDR

These sections contain this information:

Understanding TDR, page 47-15

Running TDR and Displaying the Results, page 47-16

Understanding TDR

You can use the Time Domain Reflector (TDR) feature to diagnose and resolve cabling problems. When
running TDR, a local device sends a signal through a cable and compares the reflected signal to the initial
signal.

TDR is supported only on 10/100/1000 copper Ethernet ports. It is not supported on 10-Gigabit Ethernet
ports and on SFP module ports.

TDR can detect these cabling problems:

Open, broken, or cut twisted-pair wires—The wires are not connected to the wires from the remote
device.

Shorted twisted-pair wires—The wires are touching each other or the wires from the remote device.
For example, a shorted twisted pair can occur if one wire of the twisted pair is soldered to the other
wire.

If one of the twisted-pair wires is open, TDR can find the length at which the wire is open.

Table 47-2

Traceroute Output Display Characters

Character

Description

*

The probe timed out.

?

Unknown packet type.

A

Administratively unreachable. Usually, this output means that an access list is
blocking traffic.

H

Host unreachable.

N

Network unreachable.

P

Protocol unreachable.

Q

Source quench.

U

Port unreachable.

Advertising