BYOD MacBooks are not playing nice with our Aruba wifi network.

I'm wondering if anyone else has seen similar behavior to this and if so what they did to fix it. Also open to any other helpful suggestions:

We're on a college campus running Aruba wifi with ClearPass. ArubaOS version 8.3.0.5. We have a mix of almost every model AP Aruba's ever made, AP-105 up through AP-325s. If it matters, our routing/switching gear is all Cisco. Since the beginning of the semester (August) we've had students report two similar but different issues with MacBooks on our network. These MacBooks tend to be newer on the most current version of code, but aren't all identical models, they're personally owned student devices. The issue also isn't specific to one model of AP, we've seen it on both the newer and older models. Our ClearPass implementation is decently new, it went in in May.

In both scenarios the MacBook shows up as connected to an AP (on the controllers/MM and the MacBook itself) yet cannot pass any traffic, even arp or dhcp. We have packet captures from the client side that show it is sending ARP requests and DHCP discovers but getting no responses.

Scenario 1: The user opens the MacBook after it has been closed for an extended period and moved to a new location. It takes 30 seconds to 3 minutes for the wireless to start passing traffic. Logs show it connects to an AP immediately. It then reconnects, usually to the same AP after some period of time (seconds to minutes). At that point it starts passing traffic as normal. If the user cycles the wireless adapter it starts passing traffic immediately.

Scenario 2: The user has been stationary and usually active (but not always) on their MacBook for some period of time (40 minutes in the last reported case). They suddenly lose their internet connection, the Wifi symbol gets an exclamation point in it and the MacBook says it is searching for Wifi. They are usually close to the AP they are connected to with good signal strength. This scenario will continue until the user moves to a new location or cycles their wifi adapter. Packet capture from the client shows unanswered ARP and DHCP discovers. Packet capture from the controller for the clients MAC shows no traffic at all to or from the client. The DHCP server does not see the discover packets.

Aruba TAC has been engaged but has no idea what is happening. Here's the added bonus, my networking staff can't reproduce the issue. We've only seen it happen on student machines (they've brought them to us), but we haven't been able to get one of our in house Macs to exhibit the behavior. As we can't reproduce it for TAC on demand, they don't seem to be interested in troubleshooting further. We have tried different power level settings, disabling Airgroup and setting “Force 5Ghz” with no change in the issues. We're trying a software upgrade this weekend to fix an unrelated issue, but we're not hopeful it'll help.

If anyone's seen anything like this, I'd be forever grateful for any information you could pass along. Thanks!