I have a 3560G Cisco switch that was running IOS version 'c3560-ipbase-mz.12.2-(35).SE5'. I wanted to use the IP SLA feature but this wasn't available in this version so last night I upgraded to version 'c3560-ipservicesk9-mz.12.2-(46).SE'.
This is where the problem is......in one of the GBIC ports I have a fibre link to another device and this was working fine prior to the upgrade. After the upgrade the link light on the port is not showing up. I have checked the fibre end-to-end and it is 100% OK, I have rebooted both devices, checked all the interfaces are configured correctly and changed ports however there is still no link.
I can see the red laser coming through the fibre so that is definately OK. I'm thinking this newer IOS version doesn't seem to like the GBIC's for some reason.
One other thing to note that may be relevant or not. I had a telnet session open to the switch with terminal monitor enabled and when I returned from rebooting the remote device and checking the fibre I had this message:
000061: *Mar 1 03:41:58: %LINEPROTO-5-UPDOWN: Line protocol on Interface Gigabi
tEthernet0/27, changed state to up
indicating that the switch must have recognised something on the line
Any ideas what might be happening?