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New Member

Cisco 3560 Uplink port flashing issues

I have a Cisco 3560 switch with sfp uplink to distribution switch. I noticed that the uplink port (dot1q trunk) was flashing amber then green then amber then green. I watched it do this for a good 10 minutes then the link just went dead. I checked the port and it didnt err-disable, it was just down down.

Has anyone experienced something like this or does anyone know what might cause a problem like this.

No errors were detected on the interface.

Thanks in advance.

  • LAN Switching and Routing
Hall of Fame Super Gold

Re: Cisco 3560 Uplink port flashing issues

SFPs are a funny lot. Make sure that it's inserted properly. Unfortunately, it was not designed to "click" if done right therefor you don't know whether or not the link didn't work because the module wasn't inserted properly.

A few days ago, I connected a SFP from a 2960 to a 3750. The 2960's SFP LED is green but the 3750 is not lit. It only started to work when I pulled the SFP in the 3750 out and pushed it in and exerted a little hard until the light went on.

New Member

Re: Cisco 3560 Uplink port flashing issues

I'll be sure to check the sfp but would that cause the amber to green to amber ect.. issue?