Cisco Catalyst 3650 series Command Reference Manual page 972

show cable-diagnostics tdr
If an interface does not support TDR, this message appears:
% TDR test is not supported on device 1
Related Commands
Command Description
Runs the Time Domain Reflector (TDR) feature on an interface.
test cable-diagnostics tdr
Command Reference, Cisco IOS XE Everest 16.5.1a (Catalyst 3650 Switches)
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