Catalyst 3850 Stops Providing PoE

[timothy.lewis]

Today users reported that network services were down.  The end user equipment is connected as such:

PC>Cisco Phone>Catalyst 3850 /w PoE.  The switch is a 24 port switch.

When the issue occurred all the phones were dark/powered off.  Network hosts that were not connected via phone were up and accessible.  During troubleshooting, I did a shut/no shut on the switch interface that connected to the user's phone.  Once "no shut" was issued, ALL the previously powered off phones booted & registered.  All network services were restored.

I ran "show logg" on the switch and there were no log references other than occasional interface up/down.

show power inline shows that I have seven 8961 phones and two access points.  It also shows that I have 450 Watts available, 97.3 Watts used & 352.7 Watts remaining.

[Charles Hill]

Were the ports in err-disabled state? 

When the port is down, show interface status err-disable will show the reason for being disabled, if its disabled. 

What is your ios?

If you have 3850  ios 12.2(32.8.11)SX150, there is a bug CSCui93088

"Current POE debugs do not have sufficient info about the exact cause of power being denied to a PD if it does not conform to one or more of the IEEE specs ."
 

[timothy.lewis]

No interfaces were in err-disable status.

IOS image = cat3k_caa-universalk9

IOS version = 03.02.02.SE

[Charles Hill · Accepted solution]

Below is a bug that affects your release.

One of the two work arounds is to do a shut and no shut.

Second work around is plug a non Poe device into the port then plug the Poe device back into the port.

there are known fixed releases, so an upgrade to one of the releases listed should resolve your trouble.