How to remove wireless devices from airport extreme?

You can do it by using a closed network. In a closed network you add each new device's MAC address to a list. It is a configuration option in Airport Utility. Only devices whose MAC address is in the list can join the network. Removing a device from the list prevents it from logging in anymore.

Please provide screen shots of this feature. There is an option to "Hide" the network (which is a joke), but no "list" that I can find associated with the option to "hide" a network.

As you know, there are any number of free utilities that will display a "hidden" network in seconds.

Maybe you are thinking of another brand of router, or thinking of Timed Access...which does not really work the way that you describe?

If your network is using the same wireless network name and password to which devices have connected in the past, then those devices will be able to connect to the network in the future.

Therefore, the only reliable way to keep those devices from connecting in the future is to change the wireless network password.....and then give that new password only to individuals whose devices you want to allow to connect to the network.

There are a couple of other unreliable ways to try to keep devices from connecting to your network, but our guess would be that you would not be interested in wasting your time on things like this.

An extremely limited range of DHCP addresses might be a workaround, if you could trust the router to actually work correctly.

Some things never change. The easiest, simplest, fastest, and most secure thing to do would be to change the wireless network password, and create a new strong password.

You can do it by using a closed network. In a closed network you add each new device's MAC address to a list. It is a configuration option in Airport Utility. Only devices whose MAC address is in the list can join the network. Removing a device from the list prevents it from logging in anymore.

A device will have to be connected to the network for you to even see the MAC Address of the device, so you are going to be spending a lot of time to try to watch for devices that are connecting.

Timed Access is not reliable, and not recommended for any device which has already connected to the network in the past using the same password that you are using now. It's your call if you want to try this.

AirPort Utility 6.x versions do not display MAC Addresses for devices which are connecting using Ethernet. Even if it did, there are no controls to prevent wired devices from connecting.

If you have an iPhone or iPad, try a utility like Fing to see if it will display wired devices.

The Apple routers are totally lacking in controls.

Turn off DHCP and use only statically assigned IP addresses. Nothing depending on DHCP will then be able to connect.

Alternatively you can use an extremely short range of addresses and allocate all of them statically via dhcp reservation. Then if people attempt to connect they simply will not get an IP. This is not foolproof.. almost nothing is.. but it will stop all but the most determined.

Perhaps explain why you have such a problem.. because a simple change of password will remove everyone who should not connect.. it is not that hard to change password on a half dozen devices.. never hand out this password.. if you wish to give temporary access use the guest network and shut it down when finished.