The client is now able to pass traffic to the access point.

The access point will reply with an association response.

Upon successful authentication, the client will send an association request frame to the access point.The access point will send an authentication reply.

The client decides which access point (AP) is the best for access and sends an authentication request.Access points within range respond with a probe response frame.The client can also broadcast on its own probe request frame on every channel.The Access points continuously sends out Beacon Frames which are picked up by the nearby wlan clients.By taking this approach the RF connectivity issues surface and can be corrected before we can move to stronger encryption and higher layers of the OSI layer.Īuthentication in the 802.11 specification is based on authenticating a wireless station or device instead of authenticating a user.Īs per the 802.11 specification client authentication process consists of the following transactions as mentioned below

To find cause of the wlan problems occurring in the wlan network relating to RF environment it would be best to test the wlan network using open authentication without any security. Management and control packets are dedicated to these coordination functions. In a wlan RF environment the radio transmission conditions can change so dynamically, coordination becomes a large issue in WLANs. We will need to comprehend each frame type occurring in the operation of a wireless LAN and solving network problems. Taking wlan sniffer traces using tools like omnipeek and or wireshark one can monitor the communications between radio network interface cards (NICs) and access points. Trying to analyze or troubleshoot a wireless LAN, network using 802.11 packet analyzer will require us to have a thorough understanding of different 802.11 frame types as a basis for finding pointers to localize the causes of the problem area in a wlan network. 802.11 Sniffer Capture Analysis - Management Frames and Open Auth 802.11 – Frames and open authentication

Wifi packet sniffer