Open System to WEP Authentication

The major problem inherent in an open system is that anyone can potentially
eavesdrop on everything you transmit from the wireless workstation
to the wireless router/server. The best defense against open system
problems is to migrate to WEP authentication, thereby giving yourself
protection in many ways equivalent to using a wire-based LAN system.

When you have several access points configured with the same WEP
key, it is important to note that your access point can use another form
of optimization. The wireless NIC card first attempts to execute 802.11
authentication using the WEP key acquired by the older access point
and uses that value as the shared key. If that method works, then the
access point usually adds that wireless workstation to the authenticated
access list and allows that user to access all the resources of the internal
corporate network.
However, if that authentication does not work, then the wireless NIC
card will use the open system authentication method to communicate to
the access point, thereby authenticating that wireless workstation to the
WLAN.

The access point’s job is to determine if that wireless workstation
used an open system authentication or execute a shared-key authentication
method when logging into the WLAN. If that wireless workstation
acquired access to the new access point using shared-key authentication,
then the 802.11 authentication will be started by the new access
point to update its logs concerning that wireless user.

When you allow a wireless workstation to connect using shared-key
authentication, the new access point makes certain that the wireless
workstation does not experience any problems with its network connectivity.
Should the wireless workstation not be able to authenticate itself
correctly to the new access point, the wireless workstation network connectivity
through the access point controller port is stopped in an
attempt to maintain network security.