Cisco 3850-24XS Interface shows connected with no cable.

[EricCasey]

I'm running into an issue recently after we migrated all our switches from Brocade over to Cisco 3850's.

We have Cisco 3850-24XS with GLC-GE-100FX SFP's connected to a media converter then to a workstation and traffic is working fine.

At some point the interface will stop working and if I log into the switch and show the interface it says connected.  I will unplug the fiber from the media converter and the switch interface still shows connected.  I plug the fiber back in and I get fiber lights on my media converter but no traffic is being passed.

I can unplug the fiber from the switch and the interface still shows it's up/up even with no cables connected.

The only way to get the interface back up is to shu/no shu that interface.

Any idea why we are seeing this issue?

Thanks

Eric

[Reza Sharifi]

That is most likely a software bug. Try upgrading to a different version and test again.

HTH

[Leo Laohoo]

I remembered reading this behaviour (with a 100BaseTx) as a bug.
What is the firmware the switch is running on?

[EricCasey]

We are currently running IOS XE 16.3.6

I'm going to work on upgrading to 16.9.1 but need to do some internal testing first.