CW917x PoE problems ?

[thomasthomsen]

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.

[cmr]

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)

[thomasthomsen]

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.

[cmr]

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!

[RaphaelL]

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

[thomasthomsen]

I have also never had any problems with CW9178.

[AlexanderN]

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

[thomasthomsen]

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.

[thomasthomsen]

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....

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.

[thomasthomsen]

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.

[thomasthomsen]

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.