Some users can't see open Wifi SSID

[Koldts]

Hello,

I run an enterprise network for an education institution

I've been informed that in one of our sites some users are not able to see our open wifi SSID (Completely open with optional OWE Transition on a hidden SSID). These users can see eduroam and our own password protected wifi, but not the fully open one. This is for both domain joined PC's and for student PC's. I can see users connected to the open wifi on both 2,4 and 5 GHz on the site, so not all users have this problem. I have a front service colleague that are not able to see the open wifi on his newly deployed PC, but can see it on his phone. The wifi setup is exacly the same on all our sites.

I think the problem started a month ago when we upgraded our 9800-40 to 17.9.4 from 17.3.6. All our AP's are 9120AX.

Do anyone have a clue what could be happening with the clients?

[Leo Laohoo]

Some people can see the SSID and some don't is a sure sign that those who cannot see the SSID have a wireless client that only has 2.4 Ghz. 

This means that FRA has kicked in and disabled 2.4 Ghz on some certain APs.

[Koldts]

I will try and see if i can find anything on my colleagues PC.

[Koldts]

In Prime i can see the AP my colleagues pc is on, running XOR (2,4 GHz) radio and also 802.11a/n/ac/ax radio. The PC was using 5GHz on the wifi card. We also have a policy GPO for our deployed PC's to prefer 5GHz.

[Leo Laohoo]

If the clients are capable of 5.0 Ghz, then it could be CSCwc06293.

[Koldts]

We upgraded to 17.9.4 about a month ago (where the problem might have started, i just got notice of this last week), can't see any caveats on beacons in the 17.9 release, and the bug report says it shouldn't be that problem after 17.6

[Leo Laohoo]

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@Koldts wrote:
and the bug report says it shouldn't be that problem after 17.6

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Raise a TAC Case and get TAC to confirm.

Good luck.

[Koldts]

I have been to the location and can confirm my windows PC can't see the SSID either. My iPhone can though without any problems. In another building on this faulty site there is a single AP that can i can see our open guest SSID on (on PC), and i can connect to it without a problem.

The only difference between this site and where my office is connected is this site is connected to our Datacenter through a MPLS line, and my office is through dark fiber.

[Rich R]

I'd say the most likely cause is faulty WiFi driver on the PCs.
What network adapter and driver version are displaying the problem?

If you're using Intel WiFi then make sure you have the latest Intel driver installed:
https://www.intel.com/content/www/us/en/download/19351/windows-10-and-windows-11-wi-fi-drivers-for-intel-wireless-adapters.html

If you suspect the APs might not be broadcasting the SSID then you should ask TAC about https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwh50681
If that's the case I would try to remove all WPA3/OWE from the WLAN and see whether that makes any difference.

[Koldts]

Hi Rich.

The SSID is being broadcasted, i can see that in the AP's CLI, people are connected to it.

I can see the SSID on my own PC on one site, but not on the one having the problem.

I opened a TAC case last week and he's trying to replicate the problem in his lab. He had never seen this issue before.

[Rich R]

And have you checked the client drivers?

[Scott Fella]

Just out of curiosity, have you tried to disable OWE transition to see if folks can see the SSID?  You can always create a new open SSID without OWE transition and have someone onsite validate if they can see the SSID or not.

[Koldts]

Rich: When i went from my office i could see the SSID, when i came to the site i couldn't. I updated my drivers (Qualcomm WCN685x) through Lenovo System update, and still couldn't see it.

Scott: I have not tried to disable OWE transition. We use a global policy on all our sites for this WLAN, no site specific policy, so i wouldn't be able to do this outside of our service windows. Our TAC guy did say they have seen that bug where they disable it and enable it and it works, but this was on site specific policy tags.

With the TAC guy we tried to create a new test WLAN, though with a PSK on it, and it showed on the remote PC i have available on the site instantly.

[Koldts]

So a new status:

Our TAC Case guy tried to create our network in his LAB, and he couldn't see any problem at all. When I went to the site with the problem in the Autumn holiday a few weeks ago, the network were there and everything was fine so i closed the TAC case. A week later when everyone came back, the problem was present again, this time on other sites as well.

We are sure that this problem might have been because of convergence on our WLC or something along that road. After disabling our hidden OWE network and splittting all our IoT networks to a new virtual WLC we no longer see the problem on any site.

[Rich R]

How many BSSID's did you have per radio and per AP?