Within the wired world, to associate to the network you'd plug in your Ethernet cable into the switch. Within the wifi world, you must interface to the get to point. The method of interfacing to an get to point is called the 802.11 State Machine. How does the station (STA) and get to point concur to this association? I’m reaching to endeavor to break it down step-by-step on this post.

802.11 State Machine

STA connecting to an open SSID. Summary is as follows:

- STA becomes authenticated and unassociated

- STA is unauthenticated and unassociated

- STA becomes authenticated and associated

Probing

The STA starts the method by performing a passive or dynamic check. Within the detached mode, the STA is tuning in for reference points from an get to point. The signal outline contains the BSSID which is the MAC address of the radio sourcing from the get to point. The reference point outline could be a sort of administration outline characterized in 802.11-2007. It incorporates capability data and parameters.

Scan

A test is sourced from the STA asking to connect a remote organize. Typically a test ask administration outline. The probe is reacted by an get to point employing a test reaction administration frame. In the probe ask you may discover the parameters as appeared underneath. Usually an illustration test ask from a STA broadcasted to any get to point that can react.

Authenticate

The probing/scanning stage is portion of the unauthenticated and unassociated step. The STA has not confirmed with the get to point additionally isn't related with the get to point. Think of confirmation as stopping a computer into a harbour on a switch. The STA must be confirmed to the get to point before it is related. It sounds in reverse. These are the two states in this phase and it must be wiped out this order.

There are two states in Confirmation and Affiliation:

- Unauthenticated or authenticated.

- Unassociated or associated.

To start the Verification step, the STA sends an Confirmation remote administration outline to the get to point. The get to point reacts with an Affirmation outline.

The Verification is set to a state of 1. The get to point will recognize the Verification outline from the STA and upon effective confirmation, the get to point will send an verification outline to the STA with an Verification Arrangement with a State of 2, for success. Access point sends an Confirmation outline with a state of 2.

Open System and Shared Key

If Above successful authentication frame, the Authentication Algorithm was set to Open System. There are two types of methods for authentication.

- Open System

- Shared Key

Open Framework performs no client verification. This can be the strategy utilized with SSIDs utilizing WPA, WPA2, and those with no password. Shared Key employments a passphrase and contains a 4-way handshake for confirmation. The STA sends a ask to verify, get to point gets the ask and sends back a cleartext challenge, the STA scrambles and sends another authentication request based on the cleartext challenge and after that the get to point compares the STA’s challenge to the content. In case effective, the STA is verified.

Association

Once the STA is confirmed to the get to point, the following step is to ended up Related. The Affiliation happens after the Shared Key Verification or Open Framework Confirmation Calculation. There cannot be a STA that's Related but not Confirmed. In the event that the STA falls flat Verification, it does not move to Association. After the the get to point sends an Affirmation to the STA’s Confirmation Reaction, the STA sends an Affiliation Request. The Affiliation Ask is Recognized by the get to point which at that point sends an Affiliation Reaction outline to the STA. If the affiliation is fruitful, the get to point’s Affiliation Reaction outline will contain a Status code: Successful.

- Capabilities Information such as

- Supported Data Rates

- HT Capabilities

- HT Information such as the Primary Channel

- WMM information
https://mobileinfoworld.com/802-11-state-machine/