Regarding FSSO logins

 Hi Anjali,

Please find the below link to find the basic working of FSSO:

https://community.fortinet.com/t5/FortiGate/Technical-Tip-FSAE-Troubleshooting-Guide/ta-p/190598?externalID=FD31819

The working of FSSO would be based on the windows event login of the user on the AD. So after configuring FSSO with the fortigate and AD. The Fortigate would poll for user login of the windows events on the AD server. 

The Collect Agent installed on the AD server would collect the require windows login events and sent it to the Fortigate firewall with the user login and IP address from the collect agent would create a entry on the authentication table to allow user to access the resource on the network 

Regards