iphone not connecting to 802.11ac

[rlaudiano]

any idea why iphones and ipads are not connecting to 802.11ac? it is always connecting to 802.11n. even if i turn-off wifi off and then on, it is sticking with N. anyway i can configure the controller to allow these devices to always connect to AC?

2504 WLC 8.5, 3602i with AC modules

[patoberli]

Are the AC rates enabled on the WLC? Wireless -> 802.11a/n/ac -> High throughput
What security/encryption settings are configured on the affected SSID?
Which exact version of 8.5?

[rlaudiano]

yes, under high throughput - 11n and 11ac modes are enabled

security - wpa2 + 802.1x, FT adaptive

software version 8.5.131.0

[Scott Fella]

The iPhone and iPad are newer devices that have 802.11ac NIC’s correct?  Test with an open SSID and see if the devices negotiate. If other devices negotiate to ac, you don’t have an issue with your configuration, just might be the device. 

[rlaudiano]

phones are iphone 7 and 8, ipads are a little older i think ipad air but shouldn't have any problem with their NICs as they used to connect through 802.11ac before.

tests done with open authentication have the same results sadly. i did try to change wireless-advanced-network profile-client network performance-default to throughput and test with my phone, it did connect to 802.11ac once but after turning off then on wifi it goes back to 802.11n. so something from the controller should have been configured wrongly i guess

[Scott Fella]

Here is something that might not be related but may. We ran into an issue with devices not connecting to 802.11ac and it was due to uploading a configuration file that wasn’t in the proper format. Rebuilding the controller was the fix. This affected all devices, not just Apple devices however.

Bounce the the AP and or the controller and see if that fixes the issue. When I mentioned open, I really meant to create a new SSID and set it to open, don’t change anything else on the wlan and see if that helps. Might be a config issue but who knows.

[rlaudiano]

Just a follow-up, so I have solved this issue by moving my 7921g wireless phones from 5ghz to 2.4ghz and now all devices are able to connect to 802.11ac. Problem now is these 7921g phones is always disconnecting from wireless network "leaving service area" when in 2.4ghz and very unstable.

[Leo Laohoo]

What firmware is the 7921G working on?

[rlaudiano]

firmware 1.4.6.3

[Leo Laohoo]

Can you please upgrade to 1.4(6)8?

[Leo Laohoo]

What is the settings for the SSID? Is both WPA & WPA2 enabled?
What happens if the the phone tries to connect using open authentication?

[rlaudiano]

yes, wpa and wpa2 are enabled. i have tried with open authentication local web policy and the result is still the same.

i didn't have these problems before and i used to connect to ac just fine so it just surprised me that i can no longer connect to ac. last time i did some re-configuration was about 6 months ago so its hard for me to recall the last changes i have done.

[patoberli]

Your channel width is 80 Mhz or only 40?
I assume you have NOT selected TKIP, right?

[rlaudiano]

yes, channel width is 80 Mhz. No TKIP

[Leo Laohoo]

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@rlaudiano wrote:

yes, wpa and wpa2 are enabled

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Choose only one.  It is either WPA or WPA2.  Don't turn on both and "hope" the wireless clients can make the right decision.  The wireless clients won't.