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PSA: Avoid CBS350 Switches - Critical POE Defect

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Hello Community,


I'm writing to let you know that there is a critical POE defect in the CBS350 switches and you should avoid them if you require stable POE operations. This apparent software defect causes POE ports to randomly fault after 8 to 12 hours and the powered device will go offline. Cisco does not have a resolution, workaround, or timeline to address this situation.


Please help Cisco prioritize this issue by opening a TAC case if you are experiencing this issue. Additionally, please escalate this for additional visibility through your sales channels.


All the best!

1 Accepted Solution

Accepted Solutions

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During beta testing with Cisco TAC, I can confirm this issue is resolved in Software version and MCU version 0xF0. Unfortunately, I do not have a release timeline available; however, I encourage you to reach out to Cisco TAC if you are experiencing this issue.

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54 Replies 54

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Can't say that I have seen this on CBS350-10Ps, which switch model/s are you experiencing this on and which devices are falling over?

I'm observing this on CBS350-24P-4G and CBS350-8P-E-2G running firmware. What version of firmware are you running?

What PDs are faulting?

This issue happens on ports that do not have any powered devices connected. For the ports that do have powered devices, they are:

  • Ubiquiti Access Point AC Long-Range (UAP-AC-LR)
  • Ubiquiti Camera G3 Bullet (UVC-G3-BULLET)

And what happens when they fault?

This issue happens on ports that do not have any powered devices connected as well. When the CBS350 switch faults the port, it no longer supplies power to the port and the powered device turns off.


Also on a CBS350-8P-2G. 

Have yet to see a PoE issue myself and have been running a fair few PoE (not +) devices. Concerning to hear of the issues.

Thanks, @jimstewart77 ! Could you share the output of show power inline from your CBS350-8P-2G?

kauwbergSW#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 CBS350-8P-2G 60 10 (17%) 38 TPS2388 - 0x40C4

Interface Admin Oper Power (W) Class Device Priority
---------- ---------- ----------- ----------------- ----- -------------- --------
gi1 Never Off 0.0 - low
gi2 Auto On 5.673 4 WiFiAP low
gi3 Auto Off 0.0 - DMRhotspot low
gi4 Auto Searching 0.0 - low
gi5 Auto Searching 0.0 - low
gi6 Auto On 3.056 0 low
gi7 Auto On 1.231 1 low
gi8 Auto Searching 0.0 - low

Level 1
Level 1

randomly ran into this article on UAP items and issues with Cisco Catalysts, wonder if its related to your issue