topic Re: CW917x PoE problems ? in Wireless

CW917x PoE problems ?

Thomas Obbekaer Thomsen — Thu, 19 Feb 2026 21:45:53 GMT

So ... after now having deployed some / a few / lets say a couple of hundred ... CW9176 and CW9172 APs there seems to be "something(tm)" going on with PoE for these devices.
But no-one seems to talk about it ? - Or am I just the unlucky one ? 🙂

I have learned that there is a specific issue with CW9172 and certain MS120 switches (I dont know if Im allowed to discus publicly, there are known BugIDs on this - go look if you have access).

I have also fallen into the trap of thinking it was the AP (CW9172) because of PoE issues with the MS150 (resolved through software it seems, not the mentioned -MP PoE++ problems from the release notes, but "something else" with PoE on that switch model).

But what is going on with the CW9176I's that I have deployed.
Usually they just power on fine, connects, works, no worries and everyone is happy.

But once in a while, they seem to power on (led on) and starts to go through their boot and discovery process, but then, just as the first few packets are exchanged with the dashboard (we can see this on packet captures) , it reboots, seemingly loosing power, and starts over.
Moving the AP directly to the switch (aka. to make sure its not cabeling and even switchport) does not seem to resolve the problem.
From cases created, there is nothing to see on the "Meraki end of things", and RMA was suggested from support.
This was happening "often" / "only" (cittaion needed), on Catalyst 9300 switches.
"For fun" i took the failing APs to my lab, connected them to another switch (MS130-12X) and they booted and connected just fine.

Have anyone else seen this ? Can I have my sanity checked here ? 🙂
(And of course I should have done some PoE debugging, I know this now in retrospect, but still .... 🙂 )

Thanks.

Re: CW917x PoE problems ?

CMR — Thu, 19 Feb 2026 22:03:56 GMT

What firmware are you running?

This is in the 32.1.5 fixes list:

APs that require 802.3bt PoE for full capability request greater than 30W via CDP when connected to 802.3at (30W-capable) switch port (Wi-Fi 7)

Re: CW917x PoE problems ?

Raphael_L — Thu, 19 Feb 2026 23:25:04 GMT

I had a CW9178 and CW9176 connected to a MS225-24P for ages and havent felt any issues , but my sample is very small

Re: CW917x PoE problems ?

aneduzhk — Thu, 19 Feb 2026 23:42:06 GMT

@Thomas Obbekaer Thomsen could you please let me know the exact combinations of switches + APs and corresponding firmware?

Re: CW917x PoE problems ?

Thomas Obbekaer Thomsen — Fri, 20 Feb 2026 07:03:51 GMT

This could of course be it. - Because I had the 9176 that supported demed RMA ready, connected to my home lab MS130 (where they booted, and where happy), and now today connected them back to on the same site that had problems yesterday (with more then one AP), and now it works on this site.
The site have C9300L-24P-4G.

The problem here is of course that you do not know what you get (Like a box of chocolates ? 🙂 ) from a new shipment of APs 🙂 - So you can potentially be in some serious problems if you dont have another switch to "pre-deploy" them on.

Re: CW917x PoE problems ?

Thomas Obbekaer Thomsen — Fri, 20 Feb 2026 07:05:12 GMT

I have also never had any problems with CW9178.

Re: CW917x PoE problems ?

CMR — Fri, 20 Feb 2026 07:08:53 GMT

I've seen it before on other (non Cisco) PoE devices. Sometimes it's a particular switch, sometimes a particular cable. PoE seems more finicky than I'd like, so a good PoE tester to know what you get in each case is a great (if not cheap) investment. Glad it's working now!

Re: CW917x PoE problems ?

Thomas Obbekaer Thomsen — Fri, 20 Feb 2026 08:20:25 GMT

I have seen the problems with CW9172 not powering on at all on multiple different switches, not just MS120 (and the MS120 is its own thing). - Also on MS130 and MS150 switches.

The fun thing is if you leave the AP on the switch (where it still does not get power), then perhaps after a couple of hours, it will power on, and connect. (I think I found a bug about this yesterday

It seems ... seems, to be fixed on the latest recommended release, but again ... if you get a new AP from the factory, what software does that run ?

The 9176 I have only had a couple of singular times, but always, it seems, that it actually get power, but then, after a short while, it just reboots, and then repeat.
Mostly (always?) on C9300 switches - I have not that many customers with CW9176 and MS switches.

Re: CW917x PoE problems ?

Thomas Obbekaer Thomsen — Fri, 20 Feb 2026 08:36:19 GMT

Some of it was being discussed on the Cisco Community side at some point.
https://community.cisco.com/t5/wireless/cw9172i-increased-cabling-sensitivity-poe-detect-issues/td-p/5329049#:~:text=CW9172I%20has%20increased%20cabling%20sensitivity%20and%20experiences,or%20%22power%20given%20but%20not%20good%22%20errors.

I have just had the experience that the CW9172 failed not powering on on MS130 and MS150 switches (non mGig versions). - But all of a sudden , after hours, it would just boot.
We have seen, on a previous release, cant tell you which one, that when we upgraded the CW9172, and they rebooted, they would be stuck in the same manner, not getting PoE.

It seems, that CW9172 on the latest recommended release are ok. But as mentioned, if you get a new shipment, that might contain older software, you might be in trouble.

So I think the CW9172 problem is "resolved", but Im worried about the CW9176.
This is not the same problem of course, because the AP powers up, but at some point, just shuts down, and starts over.

Re: CW917x PoE problems ?

Thomas Obbekaer Thomsen — Fri, 20 Feb 2026 08:42:16 GMT

Its C9300L-24P-4G running 17.18.2 in "meraki mode" (I cant get used to the "new terminology".) , and the APs are running ? ?? - I dont know, because they are new from the factory.
If they ever got around to downloading new software, it would be the latest recommended 32.1.6 , but the AP never gets that far.
When I got them upgraded, by having them connected to a MS130-12X running the latest MS18 software, and brought them back to the C9300L-24P-4G they booted and connected, and have stayed online as expected.

Re: CW917x PoE problems ?

Thomas Obbekaer Thomsen — Fri, 20 Feb 2026 08:50:09 GMT

Actually come to think of it. I do have some more information.

we have been installing the CW9176I at the same customer, same switch, same switch software.

And the first 15 sites no problems, but then it started.
So Im betting that we had open a new box (they come in boxes of 5) of CW9176 that might have been a little bit different. - Just a thought.

The first AP where we had the same problem, we tried a lot of things, and after 30 - 40 mins, it actually just came online, without us having done any changes to configuration or just troubleshooting, like unplugging the AP, packetcaptures, cable tests, cycling the port and so on.
- But the second AP from that "carton" we never got online, and we also tried the 3rd AP, also never got online (this was another site, this customer has many small offices, so almost only one AP pr site, but same model of switch and software). - We created a case, and support told us RMA, as mentioned, but I was curious, so I took those two APs back to the lab got it online, and now it works fine on the customers site.

Re: CW917x PoE problems ?

aneduzhk — Fri, 20 Feb 2026 23:48:48 GMT

@Thomas Obbekaer Thomsen I'm a little confused because what you are describing sound like cloud connectivity issues, not necessary PoE issues, is that correct?

Re: CW917x PoE problems ?

danwan — Sat, 21 Feb 2026 00:03:01 GMT

When you say the CW9172 is not powering on at all, do you mean the LED doesn’t even turn on? There shouldn’t be any issues running a single CW9172 on any switches, it’s when you have a second POE device plugged in directly above or below the switch port where the CW9172 is plugged in, you may see issues with the second POE device. In that case, it doesn’t matter what that second device is, could be 9176, another 9172, an IP phone, they could see power issues.

Re: CW917x PoE problems ?

Rasmus Hoffmann Birkelund — Sat, 21 Feb 2026 17:38:11 GMT

I guess it's not just me then.

I have actually been having the exact same issue, and was discussing this with a few at the beginning of the week.

I have a CW9166 in Meraki persona, and a CW9176 in Catalyst persona, both connected to a MS120. According to the datasheet, both should be able to announce 4x4:4 with PoE+, however my 9176 is only announcing 2x2:2 on 5 and 6GHz. The 9176 is joined to a 9800 which has a power profile that should instruct the AP to do 4x4:4.

Everything seems to be in order, yet WiFi Explorer confirms that the 9176 is only announcing 2x2:2.

9176 in Catalyst mode.

9166 in Meraki Mode

Re: CW917x PoE problems ?

Thomas Obbekaer Thomsen — Sun, 22 Feb 2026 21:30:31 GMT

Well, you tell me ? 🙂
Because when I moved those APs to my home lab, with a different switch, they got online.
When I then moved them back to the customer site (most likely after a software update) they worked as expected.

What we did see was that this batch of CW9176I started to boot on the C9300L-24P, seemingly getting a connection to the dashboard (from packet captures, not from the LED status), and then, for some reason, they rebooted (lost power), seemingly without any reason. (there was no indication on the dashboard that there was a connection, but we could see the AP change its hostname on LLDP, so something happened).
And then they started over, and over, and over, and .....

Of course I cant tell you 100% if it was a PoE problem, or something else, but clearly (at least to me) something was "wrong" in the switch / AP combo , until the APs got online on another switch, and got a software upgrade.

I might just have "PTSD" from all the CW9172 PoE problems I encountered, and where there seemed to be no real answer - I mean, I now have an answer for the MS120 switches, and I think i have an answer for the MS150, but not really for other switches I encountered CW9172 problems on.

Re: CW917x PoE problems ?

Thomas Obbekaer Thomsen — Sun, 22 Feb 2026 21:36:32 GMT

Well yes, I have had "many" CW9172I APs at different customers , with different switches, where we fx. unplugged an old MR36 or MR44 AP, connected a CW9172I , and it never powered on.
I have a customer with MS130-8P-I where we have seen this plenty of times.
The other customer where we have this problem might be because of "the MS120 Q2xx PoE problem".
The 3rd customer where we have encountered the problem had MS150 switches, and there was also something with PoE on those switches.

But in a nutshell, the CW9172I never seems to power on, if you leave it there, it might power on hours later, seemingly randomly.
This could also happen if you rebooted your switch.

After upgrading customers to the latest (or before the latest, Im not 100% here) 32.1.6 MR software the problem seems to have gone away.

Re: CW917x PoE problems ?

Thomas Obbekaer Thomsen — Sun, 22 Feb 2026 22:04:03 GMT

9176 seems to do the "right thing" in Meraki mode, when I look at my local ones.
I get 4SS on 5 and 6Ghz, and the expected 2 on 2,4Ghz with the PoE+ PoE i deliver.
And I dont think I have seen the Cisco classic bug where it only runs 1Gbit on PoE+, my local ones run 2,5Gbit (as expected) on PoE+
(Currently running latest MR Beta on these).

Re: CW917x PoE problems ?

aneduzhk — Mon, 23 Feb 2026 18:24:21 GMT

@Thomas Obbekaer Thomsen please open a support case because we need to clearly distinguish between known PoE issues with CW9172 and dashboard connectivity issues for other models you mentioned. There could be potentially a few know cloud connectivity issues you are hitting and Support should be able to identify the symptoms.

Re: CW917x PoE problems ?

Thomas Obbekaer Thomsen — Sat, 07 Mar 2026 08:31:13 GMT

I will now open a case for the customer with the CW9172 + MS120 problem.

Because I dont know what the solution is, except new switch hardware ?