3com WX2200 3CRWX220095A Manuel D’Utilisation

Wired-Equivalent Privacy (WEP) is a security protocol defined in the 
802.11 standard. WEP uses the RC4 encryption algorithm to encrypt 
data. 

To provide integrity checking, WEP access points and clients check the 
integrity of a frame’s cyclic redundancy check (CRC), generate an integrity 
check value (ICV), and append the value to the frame before sending it. 
The radio or client that receives the frame recalculates the ICV and 
compares the result to the ICV in the frame. If the values match, the 
frame is processed. If the values do not match, the frame is discarded.

WEP is either dynamic or static depending on how the encryption keys 
are generated. MAPs support dynamic WEP and static WEP. 

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For dynamic WEP, MSS dynamically generates keys for broadcast, 
multicast, and unicast traffic. MSS generates unique unicast keys for 
each client session and periodically regenerates (rotates) the broadcast 
and multicast keys for all clients. You can change or disable the 
broadcast or multicast rekeying interval.

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For static WEP, MSS uses statically configured keys typed in the WX 
switch’s configuration and on the wireless client and does not rotate 
the keys. 

Dynamic WEP encryption is enabled by default. You can disable dynamic 
WEP support by enabling WPA and leaving the WEP-40 or WEP-104 
cipher suites disabled. If you use dynamic WEP, 802.1X must also be 
configured on the client in addition to WEP. 

Static WEP encryption is disabled by default. To enable static WEP 
encryption, configure the static WEP keys and assign them to unicast and 
multicast traffic. Make sure you configure the same static keys on the 
clients.

To support dynamic WEP in a WPA environment, enable WPA and enable 
the WEP-40 or WEP-104 cipher suite. (See “Configuring WPA” on 
page 290.) 

This section describes how to configure and assign static WEP keys. (To 
change other key-related settings, see “Managing 802.1X Encryption 
Keys” on page 533.)