Hi! I was doing some 3750 switch relocation. After the relocation. I realise that the fiber port have no light. after much troubleshoot of changing patch cable and swap connector of the fiber it still no light. And according to my administrator the port is still show down down. I decided to use a loop back fiber cable to test the sfp port.( I using a singlemode fiber cable as the sfp is a singlemode sfp). Once I inserted the loop back fiber cable to the sfp, the LED immediately light up to solid amber. Now my question are.
1. Does it mean the port is ok?
2. why the amber light is still on when I pull out the whole sfp?
3 How can I turn off the amber light and go back to normal? ( in order to turn off the amber light. I reboot the switch.)
4. The amber light is on is it because of error detection when doing a loop back?
5. Is this the correct way to do loop back test for fiber port. Because I was unable to find any Cisco document on testing fiber port.
I was not able to console the switch because someone remotely is doing the controlling. I am doing the hardware part.
Thanks for the support
