We have the following constellation: We have a switch cluster with three Cisco 3750G-12TS installed in one ring. After 1 year and a few months we added an uplink to a new Cisco 3750G-48TS switch via a 100Base-SX SFP, but the uplinks didn´t worked. There is no light going out of the plugged-in SFPs from type 1000Base-SX, original Cisco type. Looking on the switch the command shows, that the SFP is not recognized (= "not present")
Plug-in, Plug-out and so on didn´t helped. We tried also other ports. We removed on SFP from one port, where the switch accepted the SFP as "1000BaseSX SFP", the port status is not updated (= command "show interface status"). Now, the switches are working in a productive surrounding and there is sensible data running. It looks like that the Cisco switch 3750 is frozen (= port status). I have seen that behavior last time, when I wanted to change the switchport settings from speed 100 and duplex full to auto / auto. The switch didn´t recognized the change.
(IOS = c3750-advipservicesk9-mz.122-46.SE)
We were not able to bring up one link, because the switch didn´t recognized the SFP.
We will see. Perhaps a "REBOOT" is necessary. Is there a bug...?