Cisco catalyst 3750 Command Reference Manual page 533

Chapter 2 Catalyst 3750 Switch Cisco IOS Commands
If an interface does not support TDR, this message appears:
% TDR test is not supported on switch 1
Related Commands Command
test cable-diagnostics tdr
OL-8552-07
Description
Enables and runs TDR on an interface.
Catalyst 3750 Switch Command Reference
show cable-diagnostics tdr
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