Enabling "Hidden SSID" drops 80% of clients.

Question

Tomorrow a festival of 100K+ people fires up across the street from our building.  I have a ZD1100 with 16 7363 APs running 9.5.1 bld 50.  We use iPads to control our AV system in each conf room.  When I enable the "Hide SSID" feature on the WLAN config, 80% of the clients drop (iPads, AppleTVs, and Laptops).  I can manually go to each device and force a reconnect, but really wish this wasn't necessary.  Is this by design that if the devices can no longer see the WIFI beacon they will drop the connection?  I can understand why but I'd really like to make us as invisible as possible to all of the folks with smartphones over the next few days.  Our network is of course WPA2 protected so I'm not too worried, but always better to close as many doors as possible in these type of situations.

unknown · Answer

Thanks, good info.  I know.  It was a quick temp fix.  We had a festival of 75K+ folks for three days in the park next to our building.  I was worried about 50K smartphones trying to connect to our WLAN, so I wanted to make it invisible to keep the casual user from trying to connect.  As it turns out, it wasn't a big issue.  I only detected 20 or so rouge hotspots which seems incredibly low, but that was what I was alerted to.

alf_watt · Answer

Changing the security type or hidden flag will cause iOS and OS X devices to see the network as 'different' and they will not connect automatically. On OS X you can see this in: /Library/Preferences/SystemConfiguration/com.apple.airport.preferences.plist

Please note that 'hiding' your network adds little or no security and can cause clients to behave unpredictably. Not a Wi-Fi best practice.

michael_brown_5 · Answer

You may want to consider a new hidden network and migrate over. Then once everything is migrated cut off the visible network.  Hopefully that would result in some less downtime for your users.