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Dell
Maintenance Using TDR
The time domain reflectometer (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 reflection of the signal that returns. By examining
the reflection, 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 flapping or not coming up.
TDR is not intended to be used on an interface that is passing traffic. 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 traffic.
To test the condition of cables on 100/1000/10000 BASE-T modules, use the following commands.
1. To test for cable faults on the TenGigabitEthernet cable.
EXEC Privilege mode
tdr-cable-test tengigabitethernet <slot>/<port>
Between two ports, do not start the test on both ends of the cable.
Enable the interface before starting the test.
Enable the port to run the test or the test prints an error message.
2. Displays TDR test results.
EXEC Privilege mode
show tdr tengigabitethernet <slot>/<port>
Splitting QSFP Ports to SFP+ Ports
The 10/40GbE switch supports splitting a 40GbE port on the base module or a 2-Port 40GbE QSFP+ module into four 10GbE
SFP+ ports using a 4x10G breakout cable.
NOTE:
By default, the 40GbE ports on a 2-Port 40GbE QSFP+ module come up in 4x10GbE (quad) mode as eight 10GbE
ports. On the base module, you must convert the 40GbE ports to 4x10GbE mode as described in the following section.
NOTE: When you split a 40G port (such as fo 0/4) into four 10G ports, the 40G interface configuration is available in
the startup configuration when you save the running configuration by using the write memory command. When a reload of
the system occurs, the 40G interface configuration is not applicable because the 40G ports are split into four 10G ports
after the reload operation. While the reload is in progress, you might see error messages when the configuration file is
being loaded. You can ignore these error messages. Similarly, such error messages are displayed during a reload after you
configure the four individual 10G ports to be stacked as a single 40G port.
● Split a single 40G port into 4-10G ports.
CONFIGURATION mode
stack-unit port number portmode quad
○ stack-unit: Enter the stack member unit identifier of the stack member to reset. The range is from 0 to 5.
○ port <port number> : Enter the port number of the 40G port to be split. The valid values on base module: 33 or 37;
OPTM SLOT 0: 41 or 45; OPTM SLOT 1: 49 or 53.
○ portmode quad: Identifies the uplink port as a split 10GbE SFP+ port.
To display the stack-unit number, enter the show system brief command.
● Save the configuration and reload the switch.
CONFIGURATION mode
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Interfaces