Siemens SCALANCE W788-1PRO Operating Instructions Manual page 176

Configuration Using Web Based Management and the Command Line Interface
Example
In its cell, an access point uses the setting shared key with a 128-bit public key
(default key 1) for encryption of the data traffic.
All wireless clients that register at this access point, require this public key at
position 1 in their key list for communication.
If access for certain wireless clients is now restricted by the ACL list of the access
point on the basis of a private key, the private key must first be stored in the key list
of the access point and the client to be restricted.
The next activity is to enter the MAC addresses of these wireless clients in the ACL
list of the access point and to give it the private key. If these wireless clients are
intended to continue communication, the private key must be set on the wireless
client directly under Security->Basic->WLAN and used for the encryption.
Otherwise the clients could receive broadband or multicast packets, but no longer
be addressed directly with unicast packets.
Operating Instructions SCALANCE W78x
C79000-G8976-C184-07
176