Core issue
The Cisco Catalyst 3560 Small Form-Factor Pluggable (SFP) Interconnect Cable (Part No. CAB-SFP-50CM=) provides for a low-cost, point-to-point, Gigabit Ethernet connection between Catalyst 3560 Series Switches. The 50-centimeter (cm) cable is an alternative to using SFP transceivers when interconnecting Catalyst 3560 Series Switches through their SFP ports over a short distance. All Cisco Catalyst 3560 Series Switches support the SFP Interconnect Cable.
When a Catalyst 3560 Switch is connected to a Catalyst 3750 or any other type of Catalyst switch model, you cannot use the CAB-SFP-50CM cable. The only way to connect is to use an SFP or GBIC module.
Resolution
You may connect both switches using a copper cable with SFP (GLC-T=) on both devices instead of a CAB-SFP-50CM= cable.
Note: In order to support the SFP Interconnect Cable in Catalyst 3560, you must be running Cisco IOS Software Release 12.2(25)SEA or later.
For more information, refer to Cisco Catalyst 3560 Series Switches.
Device connected to switch
Another Switch
Error message
%PHY-4-SFP_NOT_SUPPORTED:
