Our network team is working up a wifi authentication system that ties into our badging system, so a user who has badged into a building recently gets a different authentication flow.
They are reporting an issue where Macs are connecting to wireless when users pull into the parking lot, before the devices wake up and the user badges in, sending them down the wrong auth path. The only thing I can think of that would cause that is Power Nap, but is there some other mechanism that would cause a Mac to connect to WiFi while sleeping? Power Nap is disabled by default in the OS and we don't enable it.
I did some more testing today, checking my router logs after I got home from my 45 minute commute. My iPhone connected to my WiFi as expected and my MacBook, sleeping in my backpack, connected about 15 seconds later. It connected again a bit over an hour later. The wifi.log had entries confirming that. The networkoversleep option is off, but I have no sharing services enabled anyway.
I don't have a problem with this behavior personally, but it's a problem for the project, so I'm hoping I can find a way to disable connecting to APs during sleep. I'm surprised how hard it is to find information about exactly what's going on during this.
Can you clarify a bit more about “sending Macs down the wrong authentication path” ? What issues are caused by the laptop hitting the wrong Wi-Fi network? Is there a machine certificate involved? Is there a secondary agent that interacts with the login process? Are users unable to login to their laptops if it accidentally connects to an “other” Wi-Fi network?