3850 POE Issues

[quentincorbett]

We are replacing some of our older switches with the WS-C3850-48P-L.  I am having a strange issue where these switches wont power up a POE device after a week or two.  For example, I racked the switches plugged in a phone and all seemed fine.  We back to the switch about a week later to move a small amount of connections but none of the devices would power up (AP, NEC Phones).  I keep seeing "Detect: Interface Gi1/0/1: Power Device detected: IEEE PD" then "Power_Granted: Interface Gi1/0/1: Power granted" followed by "IEEE_DISCONNECT: Interface Gi1/0/1: PD removed.  Power for all ports is set to power inline auto and CDP is disabled.  I did try "power inline never' but that didn't seem to do anything as this was happening all all ports.  I decided to reboot the switches, and then they worked fine and provided POE to all devices.  After leaving them for another week with about 10 connections I went back to move the remaining connections over but ran into the same issue again, rebooted the switches again and they worked fine.  This time I took a phone and connected to every port to make sure it would provide power and they all did.  This to me seems like a bug with the switch but it seems odd that it clears with a reboot.  Would also like to add that once a device is powered up it never went down even if the switch stop providing power to new devices.  I have the switches in two different IDFs and all had the same issue.  It has been about 24 hours and all the switches are still allowing POE but I have a feeling this might fail again over time.  Really don't want to have to reboot the switches all the time to get POE to function for new devices.    

Switch Model: WS-C3850-48P-L

Version 03.06.04.E

Module Available Used Remaining
(Watts) (Watts) (Watts)
------ --------- -------- ---------
1 1120.0 198.8 921.2
Interface Admin Oper Power Device Class Max
(Watts)
--------- ------ ---------- ------- ------------------- ----- ----
Gi1/0/1 auto on 15.4 Ieee PD 3 30.0
Gi1/0/2 auto on 7.0 Ieee PD 2 30.0
Gi1/0/3 auto off 0.0 n/a n/a 30.0
Gi1/0/4 auto off 0.0 n/a n/a 30.0
Gi1/0/5 auto on 7.0 Ieee PD 2 30.0
Gi1/0/6 auto off 0.0 n/a n/a 30.0
Gi1/0/7 auto on 7.0 Ieee PD 2 30.0
Gi1/0/8 auto off 0.0 n/a n/a 30.0
Gi1/0/9 auto on 7.0 Ieee PD 2 30.0
Gi1/0/10 auto on 7.0 Ieee PD 2 30.0
Gi1/0/11 auto off 0.0 n/a n/a 30.0
Gi1/0/12 auto on 7.0 Ieee PD 2 30.0
Gi1/0/13 auto on 7.0 Ieee PD 2 30.0
Gi1/0/14 auto on 7.0 Ieee PD 2 30.0
Gi1/0/15 auto on 7.0 Ieee PD 2 30.0

Any insight on this would be greatly appreciated as we are probably going to purchasing more or we could switch back to the old 3750x.

Thank,

Quentin 

[Mark Malone]

Hi

It does sound like a bug ,checked the release notes for that version but only see one registered below for poe

There is a new versions IOS-XE out for that platform 3.6.5E I would try on one switch as a test that could save a lot of troubleshooting if its a bug

http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3850/software/release/3e/release_notes/OL3262101.html

CSCuh10592

Sys Pwr and PoE Pwr remain GOOD even when Status is Disabled

[quentincorbett]

Thanks, I have a couple of 3850s in the box I will try upgrading to 3.6.5E.

[Furose M]

There are few major PoE related bugs resolved in 3.6.5 / 3.7.4.. its kind of stable for PoE in 3850 as of now.

[quentincorbett]

I did update my switches to 3.6.5 so we will see if that helps.  Another issue has popped up where now ports 24-36 on one switch will not allow POE.  Data works fine and it but the switch won't even log any info about the POE device being connected.  I have opened a TAC to have the switch replaced.

[Furose M]

we have seen that issue in 3.6.5 but not in 3850.. hmm.. can u try 3.7.4.. most likely the problem wont be seen in 3.7.4.

[quentincorbett]

• Might try 3.7.4 if it continues even after getting the replacement switch. I went with the 3.6.5 because that's what is recommended for the 3850. I believe my the issue I have now is hardware related. POE was working after the upgrade but the just stopped on ports 24-36. Even devices that was up and running on those ports all using POE shut down and a reboot did nothing. My previous issues was that new POE devices wouldn't receive power after the switch had been running for about a week. Rebooting the switch would resolve that issue. 

[Furose M]

yeah. this is a known issue.. PoE doesnt work on 4 ports group.. i would highly suggest testing in 3.7.4 before replacing..

[lavellje1]

 Thanks, I will try 3.7.4 before removing the switch.  This is "quentincorbett"  I for I was using another account before replying.

[quentincorbett]

So just to update this issue, I upgraded the switches to the cisco recommended 3.6.5E and I am still having the issue.  Another thing I have noticed is once the switch has been up for 1-2 weeks not only does it stop allowing POE for new devices, if you unplug a device using POE it will not power the device backup once you plug it back in.  For my next attempt to fix this issue I am going to change the IOS to 3.7.4.  

[Justin3102]

This is exactly what is happening to me. I tried to Upgrade manually with a USB, but I received I/O Errors of various codes. I was stuck because The Priority switch  was in the old OS and the members in the stack had Version Mismatch, and it was fighting me with a boot loop. 

I disconnected the stack cables to stop them from forcing restarts among each other.

I tried loading from USB and got lucky when I was in Primary switch ROMMON.

I believe there is a power instability issue that also affected the way the switches read USBflash0:.

I ran int range gi 1/0/1-48

power inline never / shut

power supply switch 1 slot A off

"                                       " B off

and used the stack-power cables from another switch to repair the afflicted device. Cutting off the erratic power supplier allowed me to use the USB. (Yes, I have tried these devices on other hardware and never have received such an error. These USB devices are fine and the issue follows me on all 3850s with POE issues.)

The reverse is also true. I had another related stack but this time, I had to disconnect stack-power cables and use a standard power supply in order to stop the malicious power source from cycling through my stack. Good times.

[quentincorbett]

Changing the IOS to version 3.7.4 resolved the POE issues.  Also, my  POE devices are powering up much quicker than the previous versions tested.