Getting Android devices to work with Aruba wireless networks

This post is short and sweet since it probably affects a narrow range of people. If you run Aruba wireless gear and your Android users have started to complain about connectivity issues, here's the fix. Set "no broadcast-filter arp" on your wlan virtual-ap.

The longer story is that Aruba gear (by default) will send ARP responses as unicast instead of broadcast. This is a trick to conserve RF network capacity and extend battery life for devices. The problem is that Android (and I'm guessing Linux) devices treat the responses as invalid. It sent a broadcast and receieved a unicast response.....that does seem kind of fishy. I don't know if this behavior is against some sort of RFC or is frowned upon or what. I think it sounds neat....until it breaks stuff.

No other devices we saw (Macs, PCs, iPhones) were affected by this. The Android phones would associate with a radio, join the network, get an IP, then go nowhere. No kind of network access would work. The tell-tale test was a basic ping from the controller to the device. That failed even with static ARP entries on the controller (because the client was ignoring ARP responses).