Re: Unable to manage PoE on CBS250-8PP-D

bastian1 · ‎10-17-2022

Hi

I'm not sure if I'm holding it wrong, but I have some behaviour of a PoE enabled CBS250-8PP-D that I can't explain from the documentation. The switch is running the latest firmware 3.2.0.84.

I experience:

No PoE lights, switch does not realize it powers devices.
"power inline never" does not disable power, the port provides power all the time.
Connecting a broken device kills the power supply (I assume with a short circuit and over-current) and shuts down the complete switch.

On port GI2 I have a PoE+ enabled device (a Unifi AP 6 Pro) connected, but it does not show up as powered:

Power-limit mode: Class based
Usage threshold: 95%
Trap: Disable
Legacy Mode: Enable
Inrush Test: Enable
Guard-Band Value: Static (2W)
 
Unit Module           Nominal   Consumed     Temp     SW            PSE chipset      
                      Power (W) Power (W)    (C)      Version       HW Revision      
---- ---------------- --------- ------------ -------- ------------- -----------------
1    CBS250-8PP-D     45        0 (0%)       71       23.223.26.13  PD69208M - 0x4A02


Interface    Admin       Oper         Power (W)     Class     Device     Priority 
---------- ---------- ----------- ----------------- ----- -------------- -------- 
gi1        Auto       Searching   0.0               -                    low      
gi2        Auto       Searching   0.0               -                    high     
gi3        Never      Off         0.0               -                    low      
gi4        Auto       Searching   0.0               -                    low      
gi5        Auto       Searching   0.0               -                    low      
gi6        Auto       Searching   0.0               -                    low      
gi7        Auto       Searching   0.0               -                    low      
gi8        Auto       Searching   0.0               -                    low

Also the almost idle switch gets hotter then I would assume to be okay.

Any hints?

pieterh · ‎10-18-2022

>>> Connecting a broken device kills the power supply <<<
this should not happen, the port should have a security mechanism and shut off power to the connected device
>>> temp 71 (C) <<<
is also an indication of something not working right, this is very high

my guess is this device is broken -> contact Cisco or your vendor for a RMA

NB! some devices only work with Power over ethernet with their own power injector, that is, they do not comply to PoE (802.3af), PoE+ (802.3at) standard
but the Unifi AP 6 Pro should comply

bastian1 · ‎10-20-2022

Got a replacement. Same broken behaviour. Okay, SN shows it's the same batch of devices.

dallaswalter4561 · ‎10-20-2022

As we were also using latest firmware 3.2.0.84 from the last month for our business where we buy houses. But it was showing some sort of issues due to which our expert change the fireware. But still our expert is trying to fix the issue in firmware 3.2.0.84 because we have some important activities for which it is necessary.

JWSC · ‎08-17-2023

I'm having same issue with one of my CBS250-8PP-D.

#show power inline

Power-limit mode: Class based
Usage threshold: 95%
Trap: Disable
Legacy Mode: Enable
Inrush Test: Enable
Guard-Band Value: Static (2W)

Unit Module           Nominal   Consumed     Temp     SW            PSE chipset
                      Power (W) Power (W)    (C)      Version       HW Revision
---- ---------------- --------- ------------ -------- ------------- -----------------
1    CBS250-8PP-D     45        0 (0%)       73       23.223.26.13  PD69208M - 0x4A02


Interface    Admin       Oper         Power (W)     Class     Device     Priority
---------- ---------- ----------- ----------------- ----- -------------- --------
gi1        Auto       Fault       0.0               -                    low
gi2        Auto       Fault       0.0               -                    low
gi3        Auto       Searching   0.0               -                    low
gi4        Auto       Searching   0.0               -                    low
gi5        Auto       Searching   0.0               -                    low
gi6        Auto       Searching   0.0               -                    low
gi7        Auto       Searching   0.0               -                    low
gi8        Auto       Fault       0.0               -                    low

I have another though that's working. Both on same firmware, 3.3.0.16

show power inline

Power-limit mode: Class based
Usage threshold: 95%
Trap: Disable
Legacy Mode: Enable
Inrush Test: Enable
Guard-Band Value: Static (2W)

Unit Module           Nominal   Consumed     Temp     SW            PSE chipset
                      Power (W) Power (W)    (C)      Version       HW Revision
---- ---------------- --------- ------------ -------- ------------- -----------------
1    CBS250-8PP-D     45        5 (11%)      68       23.223.26.13  PD69208M - 0x4A02


Interface    Admin       Oper         Power (W)     Class     Device     Priority
---------- ---------- ----------- ----------------- ----- -------------- --------
gi1        Auto       Searching   0.0               -                    low
gi2        Auto       Searching   0.0               -                    low
gi3        Auto       Searching   0.0               -                    low
gi4        Auto       Searching   0.0               -                    low
gi5        Auto       Searching   0.0               -                    low
gi6        Auto       On          5.3               3                    low
gi7        Auto       Searching   0.0               -                    low
gi8        Auto       Searching   0.0               -                    low