All right, so let's illustrate the steps that take place when a client connects to an access point
and then we can visualize how the data transmission works.
So stay in a station, a client that wants to connect to an access point, AP represents that access
point.
Now, we can separate this process into three main parts, right, probe authentication and association.
So in the probe process.
The EPA first sends a probe on all channels to find the AP.
And then the apps and range answer to the probe request.
Of course, is the very first step of connection, so in this phase, the driver of the client searches
for an AP.
Then in the authentication process.
The state sends an authentication request to the AP by default to the one with the best signal.
And then it also checks the compatibility of the encryption type.
Then once compatable networks are discovered, the station will attempt authentication with compatible
access points.
And then the access point will receive the authentication frame and then it responds to the station
with the authentication frame set to open, indicating a sequence.
If an access point receives any frame other than an authentication or a probe request from a station
that is not authenticated, it will respond with a D authentication frame.
And finally, in the association process, once the station determines which access point it would be
most likely to associate with, it will then send an association request to that access point.
And then if the elements of the association request match the capabilities of the access point, it
will create an association I.D. for the station and then respond with an association response with a
success message granting network access to that Mobil station.
Now, the Steet or station can communicate with a network.
So after all of this process is finally completed, that it can then be exchanged on the network.
Now, please note that there is an other phase for an encrypted networks, there's a key exchange and
verification that will happen just after association before you're able to use the network.
All right, so now let's have a look at the authentication methods.
Now, there are two types of authentication, the shared authentication, and it's only used with weap
and open authentication.
So the steps that take place during an open authentication are basically wireless client sends an authentication
request to the access point.
The access point then sends an authentication response and the authentication process is completed successfully.
Shared key authentication is another method of authenticating with weapons labeled networks, so the
station sends an authentication request to the access point.
Access Point sends a challenge text to the station.
The station then uses its default key to encrypt the challenge text and sends it back to the AP.
The AP then decrypt the encrypted text with the Web key that corresponds to the station default key
and then compares the result with the original challenge text if there's a match.
Of course, that means they share the same key and the AP authenticates the station, if there's no
match, the AP refuses to authenticate the station.
So let's have a look at the association process in Wireshark.
So I captured the packets of association processes that took place between a phone and my access point.
So first, I filtered the results by applying the Mac address of the phone as the source address.
Then the process takes place here, so probe request authentication and association packets, respectively.
Then when we add a filter by playing the access point as the destination, we can see the response packets
sent by the access point for the association process.