If you haven’t read Jiri Brajcha’s blogs showing test results with iPad Pro and Cisco 9136 AP, I highly recommend you do so at https://www.jiribrejcha.net He does an excellent job at testing iPad’s band preferences based on channel width and transmit power levels. In this blog, I will share my findings on other tests using an iPad Pro with Wi-Fi 6E and an Aruba AP 635.

Lab Config

Aruba AP 635: FW 8.10.0.1 LSR & 8.11.0.1 SSR
2.4 GHz – channel 1, 20MHz, 8dBm, SSID: Aruba_635_2.4_8dBm
5 GHz – channel 36, 20MHz, 14dBm, SSID: Aruba_635_5_14dBm
6 GHz – channel 101 [PSC], 80MHz, 16dBm, SSID: Aruba_635_6_16dBm
SSID: Aruba_635_6_Guest
Acceltex Accelerator v2
Mikrotik hAPac2
iPad Pro 11″ 4th Gen,OS version 16.1 (20B82)
MacBook Pro M1:
Ekahau AI Pro 11.1.3 with Sidekick v2
WiFi Explorer Pro 3:
WLANPi Pro configured as remote sensor
AirTool 2:
WLANPi Pro configured as remote sensor for multi-source captures

In this lab I did not test with the same SSID across all three bands. As you can see, I had one SSID per band, with two SSIDs being advertised in 6GHz. With the initial setup, the iPad could see all SSIDs.

In WiFi Explorer Pro 3, I added a WLANPi Pro as a remote sensor and could see all networks without any problems.

Ekahau discovered all networks as well including the 6GHz SSID.

In Airtool 2, I added another WLANPi Pro as a remote sensor and in Multi-Source Capture… mode, I selected channels 36 and 101 [PSC] and performed packet captures.

I could see the beacon in 5GHz with the Reduced Neighbor Report advertising both networks in channel 101 with their respective short SSIDs.

On a separate capture I obtained beacons in channel 1 and 2.4 also had RNR. Beacons on channel 101 showed the Aruba_635_6_16dBm SSID with the Multiple BSSID element and the Aruba_635_6_Guest spelled out.

With these configurations, the iPad could successfully associate to the networks in 2.4GHz, 5GHz, and 6GHz.

I disabled the 2.4GHz and 5GHz radios in the Aruba AP 635 and now the iPad could not see the SSIDs being advertised in 6GHz. Ekahau and WiFi Explorer Pro 3 continued to see the 6GHz SSIDs. I also disabled the 2.4/5GHz radios while the iPad was associated to 6GHz and it worked until the iPad went into sleep mode, when the iPad was awaken, it could not associate anymore even if the network name and credentials were added manually.

As Jiri mentioned in his blog, the iPad relies on the RNR announced in 2.4/5GHz to discover 6GHz networks. Note that in my test, none of the SSIDs announced in 6GHz were being advertised in either 2.4 or 5GHz. Each band had its own SSID, but because of the RNR, the 6GHz SSIDs were discovered by the iPad and the iPad was able to connect to 6GHz without any issues.

Now with 6GHz only operating in the AP, I was expecting to see Unsolicited Probe Responses and Fast Initial Link Setup [FILS] frames, but I could only see beacon frames advertised in 6GHz. With the help of Santiago Carmona from Colombia, we realized that we had Firmware 8.10.0.1 LSR running. I updated the AP to 8.11.0.1 SSR and now FILS frames were being transmitted.

One thing that got my attention on the FILS, the Short SSID for the transmitted SSID was backwards from the originally generated hexadecimal value. Instead of being e468b379, on the FILS it was listed as 0x79b368e4. The non-transmitted SSID Aruba_635_6_Guest’s short SSID was listed as generated [0xb8af9480]

If you want to see the video with all the steps and miss-steps during the data collection, visit https://thewifiofthings.com/113a-sesion-de-tess-en-wi-fi-aruba-635-ipad-ekahau-acceltex-wifiexplorer-airtool-wlanpi-pro/ just be aware that it is in Spanish during our 113th Sesión de Tes@s en Wi-Fi.

I will be doing more tests with other client devices and will be posting them here.