Wi-Fi re-authentication request with iPads using MP895/MP70 devices


#1

Hi All,

So here’s the scenario and issue(s) we are experiencing, I’ll attempt to break it down/simplify it.

Devices involved:

  • MP895/MP70 Sierra Units (located in on road vehicles) unsure of firmware versions currently (we have a sizable quantity of units with potentially multiple firmware versions used)
  • iPads with Wi-Fi profile pushed down using an Enterprise MDM. Most affect iPads seem to be running iOS11.

When the Sierra units are disrupted (power cycled) we notice that the iPads fail to connect to the Wi-Fi Network (normal behavior) but then are prompted to re-enter the PSK. We have been able to replicate this issue on both models of MP’s. We have also been able to replicate the same error on the iPads when moving too far away from the MP’s. I imagine this is due to lack of/limited connectivity to the Sierra unit which is causing a bad handshake?

We also attempted to replicate the passcode prompt on a standard modem/router (iiNet Technicolor) and it did not occur and instead just disconnected and after a few minutes reconnected once the Wi-Fi Network was available again. Never did it once request for the PSK to be entered again.

We are to believe this may be related to multiple failed handshake attempts from the Sierra unit which then in turn prompts the iPad to re-enter the PSK for the Wi-Fi Network.

I have read that Cisco had a similar issue which was classified under deauth code 15 - 4-Way Handshake timeout.
https://www.jamf.com/jamf-nation/discussions/26557/ios-11-ipads-disconnecting-from-wifi-and-asking-for-password
https://www.cisco.com/assets/sol/sb/WAP371_Emulators/WAP371_Emulator_v1-0-1-5/help/Apx_ReasonCodes2.html

We also suspect that some of the older MP895 are now failing due to their age but that doesn’t particularly tell us why the MP70 are showing the same issues. We suspect that some of the MP895 devices may be rebooting constantly which is also causing this issue to happen.

Any ideas? our main goal is to determine whether or not replacing the MP895 will actually resolve this issue as replacing the units would be an expensive task if it does not resolve these issues.

Thanks
Todd Mitchell