3850 with 4 port SFP module suddenly reporting SFP module removed

[Steve Pfister]

We have a 3850 at a remote site that has been working for quite some time. The uplink back to the central site is a 4 port SFP module with a single LC fiber cable and a GLC-SX-MM SFP module. Yesterday and today, the uplink port went down/down and the logs reported that the sfp module removed, even though the module wasn't removed and no one was near the switch at all. The cables and module seem to be firmly seated. Is there anything I should check before replacing the 4-port module with a spare?

[M02@rt37]

Hello @Steve Pfister 

Please review the logs on the 3850 to identify any specific error messages or patterns that may indicate the nature of the problem. Commands like show logging or show log | include SFP can be useful.

Also heck the environmental conditions of the remote site. Extreme temperatures or humidity levels can affect the performance of the SFP module and the switch.

[Steve Pfister]

Below are the only log lines regard this issue. They show the problem occurring at 5am plus moving the transceiver and cable over to another port (which made the uplink come right up). Environmental conditions are about average I think, no extreme heat or humidity.

Aug 21 05:00:14.855: %PLATFORM_PM-6-MODULE_REMOVED: SFP module with interface name Gi1/1/1 removed
Aug 21 05:00:15.902: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/1/1, changed state to down
.Aug 21 05:00:17.024: %LINK-3-UPDOWN: Interface GigabitEthernet1/1/1, changed state to down
.Aug 21 05:00:17.903: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to down
.Aug 21 05:00:17.915: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan2, changed state to down
.Aug 21 09:04:00.483: %PLATFORM_PM-6-MODULE_REMOVED: SFP module with interface name Gi1/1/2 removed
.Aug 21 09:04:11.748: %PLATFORM_PM-6-MODULE_INSERTED: SFP module inserted with interface name Gi1/1/2
.Aug 21 09:04:21.288: %LINK-3-UPDOWN: Interface GigabitEthernet1/1/2, changed state to up
.Aug 21 09:04:25.641: %LINEPROTO-5-UPDOWN: Line protocol on Interface GigabitEthernet1/1/2, changed state to up
.Aug 21 09:04:27.736: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to up
.Aug 21 09:04:27.748: %LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan2, changed state to up

[Reza Sharifi]

If someone is in a remote location, you may want to ask them to unplug the fiber, clean the tips, and put it back. The fiber tips may need cleaning.

The next thing I would change would be the SFP before replacing the module.

HTH

[Leo Laohoo]

Cold reboot the switch.