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poe+ working but not working for some devices


hi all,

i have a cisco 3850 POE+ switch and both kettle leads are connected in to them and both PSU lights say connected and ok

on a port i plug in a voip phone and it powers it up no problem

but as soon as i connect a door to the switch it doesnt power on the control panel for the door, but the door control panel says they need POE+, so i dont understand why there not powering on

can i maybe change the power to one of the ports?



5 Replies 5

David Ruess
Rising star
Rising star



It may need more power than the switch can provide out. You should be able to adjust the power on a per interface basis. If not there are devices that plug into a wall power outlet to check POE devices. IP phones have them if there is no POS switch or port in the area. Its like a power brick for ethernet. Test on that to see if it can get power from the wall.



this is weird when i do a

show power inline

the ports where the poe+ devices are plugged in keep on changing ie one time they say on, then next they say off, so maybe theres not enough power


Is lldp and cdp enabled ?

share show power inline and show inventory. 

-hope this helps-

Gi1/0/42 static off 30.0 n/a n/a 30.0
Gi1/0/43 static on 30.0 Ieee PD 4 30.0
Gi1/0/44 static on 30.0 Ieee PD 4 30.0
Gi1/0/45 static off 30.0 n/a n/a 30.0
Gi1/0/46 static on 30.0 Ieee PD 4 30.0
Gi1/0/47 static off 30.0 n/a n/a 30.0
Gi1/0/48 static off 30.0 n/a n/a 30.0

NAME: "c38xx Stack", DESCR: "c38xx Stack"
PID: WS-C3850-48P-L , VID: V07 , SN: FCW2034F0CG

NAME: "Switch 1", DESCR: "WS-C3850-48P-L"
PID: WS-C3850-48P-L , VID: V07 , SN: FCW2034F0CG

NAME: "Switch 1 - Power Supply A", DESCR: "Switch 1 - Power Supply A"
PID: PWR-C1-715WAC , VID: V01 , SN: LIT203237PE

NAME: "Switch 1 - Power Supply B", DESCR: "Switch 1 - Power Supply B"
PID: PWR-C1-715WAC , VID: V01 , SN: LIT19240UPS

NAME: "Switch 1 FRU Uplink Module 1", DESCR: "2x1G 2x10G Uplink Module"
PID: C3850-NM-2-10G , VID: V01 , SN: FOC203519VW

NAME: "Te1/1/4", DESCR: "SFP-10GBase-SR"
PID: SFP-10G-SR-S , VID: V01 , SN: AVD2030D59D


I changed back from static to auto, still no difference, it giving out 30w and max is 30w but it keeps on turning off and back on as when I do

Sh power inline

It keeps on showing as on and off so the power keeps on going on off

I have sort of resolved it by another switch

But I would like to get to the bottom of this

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