WLAN Roaming - the basics Even if you keep the same IP address,
things get complicated. When a WLAN client moves from the range
of one Access Point (AP) to another in the same subnet, it needs
to find the best AP, decide when to roam onto it, associate with
it and do any authentication required, as per your security
policies. Then the wired network has to relearn the location of
the client, so that data can be sent to it. All of this takes
time and this is without the client having to worry about
getting a new IP address! The scanning and decision making part
of the roaming process (see How to Make your WLAN roam faster)
allows the client to find a new AP on an appropriate channel as
the user moves. When this happens, the client must associate
with the new AP. It must then, assuming that it is an 802.1x
supplicant (see The EAP Heap), reauthenticate with the RADIUS
server. This is transparent to the user - but the delay in this
happening may not be. It can take up to a second for association
and authentication