Is there any reason why this command wouldn't work on a 3560 ip-base switch?
C3560-24#test cable-diagnostics tdr interface fastEthernet 0/10
% TDR test is not supported on interface Fa0/10
Here is the config of the interface.
switchport trunk encapsulation dot1q
switchport trunk native vlan 7
switchport mode trunk
srr-queue bandwidth limit 50