Configuration / project engineering
5.5 Security Wizard
SCALANCE W786-xPRO
90
Operating Instructions, Release 08/2007, C79000-G8976-C221-02
characters, on the other hand, define a strong key (128 bits). Then select "Encryption" in
the "Basic WLAN" menu.
●
Low (Shared Key)
In Shared Key authentication, a fixed key is stored on the client and access point. This is
then used for authentication and encryption. In this case, you will have to store a WEP
key after selecting "Low (Shared Key)".
●
Medium (WPA2-PSK)
WPA2-PSK is based on the WPA2 standard, WPA authentication, but operates without a
RADIUS server. Instead of this, a key (pass phrase) is stored on every client and access
point and this is used for authentication and further encryption. AES or TKIP is used as
the encryption method, AES represents the standard method.
●
High (WPA2)
WPA2 (Wi-Fi Protected Access 2) is a further development of WPA and implements the
functions of the IEEE 802.11i security standard. WPA2 uses the additional encryption
protocol CCMP with preauthentication that allows fast roaming in mobile ad hoc
networks. A client can log on in advance at several access points so that the normal
authentication can be omitted.
A RADIUS server is used to authenticate the client with an access point. The client logs
on at a RADIUS server based on a certificate (EAP-TLS) or a combination of user name
and password (EAP-PEAP or EAP-TTLS / internal authentication method MSCHAPv2).
As an option, the RADIUS server then identifies itself to the client using a certificate.
Following successful authentication, the client and RADIUS server generate key material
that is used for data encryption. AES or TKIP is used as the encryption method, AES
represents the standard method.
●
Medium with WPA compatibility (WPA-Auto-PSK)
Select the "Medium" security level and check the "WPA compatibility"
box so that an access point can process both "WPA-PSK" authentication as well as
"WPA2-PSK". This is necessary when the access point communicates with different
clients, some using "WPA-PSK" and others "WPA2-PSK". The same encryption method
must be set on the clients.
●
High with WPA compatibility (WPA-Auto)
Select the "High" security level and check the "WPA compatibility"
box so that an access point can process both "WPA" authentication as well as "WPA2".
This is necessary when the access point communicates with different clients, some using
"WPA" and others "WPA2". The same encryption method must be set on the clients.
Encryption
Encryption protects the transferred data from eavesdropping and corruption. You can only
disable encryption in the "Encryption" check box if you have selected "Open System" for
authentication in the "Basic WLAN" menu. All other security methods include both
authentication and encryption. Various schemes are used for encryption:
●
WEP (Wired Equivalent Privacy)
A weak, symmetrical stream encryption method with only 40- or 104-bit long keys based
on the RC4 algorithm (Ron
’
s Code 4).
●
TKIP (Temporal Key Integrity Protocol)
A symmetrical stream encryption method with the RC4 algorithm (Ron
’
s Code 4). In
contrast to the weak WEP encryption, TKIP uses changing keys derived from a main key.
TKIP can also recognize corrupted packets.
