Users Guide

Maintenance Using TDR
The time domain reectometer (TDR) is supported on all Dell Networking switch/routers. TDR is an assistance tool to resolve link issues
that helps detect obvious open or short conditions within any of the four copper pairs. TDR sends a signal onto the physical cable and
examines the reection of the signal that returns. By examining the reection, TDR is able to indicate whether there is a cable fault (when
the cable is broken, becomes unterminated, or if a transceiver is unplugged).
TDR is useful for troubleshooting an interface that is not establishing a link, that is, when the link is apping or not coming up. Do not use
TDR on an interface that is passing trac. When a TDR test is run on a physical cable, it is important to shut down the port on the far end
of the cable. Otherwise, it may lead to incorrect test results.
NOTE: TDR is an intrusive test. Do not run TDR on a link that is up and passing
trac.
To test the condition of cables on 100/1000/10000 BASE-T modules, follow the below steps using the tdr-cable-test command.
1 To test for cable faults on the TenGigabitEthernet cable.
• Between two ports, you must not start the test on both ends of the cable.
• Enable the interface before starting the test.
• The port must be enabled to run the test or the test prints an error message.
EXEC Privilege mode
tdr-cable-test tengigabitethernet <slot>/<port>
2 Displays TDR test results.
EXEC Privilege mode
show tdr tengigabitethernet <slot>/<port>
Conguring wavelength for 10–Gigabit SFP+ optics
You can set the wavelength for tunable 10–Gigabit SFP+ optics using the wavelength command. To set the wavelength, follow these
steps:
• Enter the interface mode and set the wavelength.
INTERFACE mode
wavelength 1529.0
The wavelength range is from 1528.3 nm to 1568.77nm.
• Verify conguration changes.
INTERFACE mode
show config
Flow Control Using Ethernet Pause Frames
An Aggregator auto-congures to operate in auto-DCB-enable mode (Refer to Data Center Bridging: Auto-DCB-Enable Mode). In this
mode, Aggregator ports detect whether peer devices support converged enhanced Ethernet (CEE) or not, and enable DCBX and PFC or
link-level ow control accordingly:
• Interfaces come up with DCB disabled and link-level ow control enabled to control data transmission between the Aggregator and
other network devices.
Interfaces
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