Email as follows:
Dear eduroam UK community,
Over the past month, we have been investigating a significant number of flaps with Apple iPhone XS/XS Max devices on our wireless network since the issue was drawn to our attention by one of our more technical users.
We observed the following behaviour:
1. iPhone XS/XS Max joins our SSID via 5GHz.
2. The device drops soon after, usually within 30 seconds or so, and the AP cites 'extensive data loss' as the reason - this is even when the device is within a couple of feet of the AP.
3. The device then attempts to join 2.4GHz.
One of two things then happens:
4. The device joins and stays connected at 2.4GHz which is not ideal.
5. The device joins, connects but eventually sends a deauth to the AP within a matter of minutes and then attempts to reconnect at 5GHz which starts the whole process again.
The users who we tested this with have confirmed they were running the latest iOS 12.1.4 on their devices while experiencing the issue so there is currently no software update from Apple which rectifies this issue.
However, our vendor has provided us with a software update that fixes the issue and provided us with a short statement:
"Apple uses a new chip, so presumably, a new driver too. This new driver did not follow RFC recommendation in one fragmenting method. We will try to contact them about it, but currently, we made a workaround."
This would imply that the issue is with the radio stack implementation within the new Apple devices and that the issue is actually Apple's responsibility to fix.
Therefore, I am publishing this info to a wider audience as I know that a lot of you will have a significant quantity of Apple devices on your networks and so your users could also be afflicted by the issue at hand.
Please check with your local helpdesk staff to see if they are seeing this problem and if they are, please speak to your own wireless vendors about obtaining a suitable fix for your own APs until Apple sorts themselves out.
I have logged onto our customer's hive and can't find any evidence that this is happening, but we are unable to check which of their IOS devices are of the newest type
