Technical Tip: Behavior of FortiOS while testing connectivity against remote authentication servers

FortiOS performs different approaches when it comes to testing the connectivity with remote authentication servers like LDAP or RADIUS.

Testing Connectivity against LDAP Server:

FortiOS will perform a simple LDAP bind using the configured credentials against the LDAP server and if the LDAP bind is successful, the connection to the LDAP server will be considered sustainable.

Testing Connectivity against RADIUS Server:

FortiOS will send RADIUS Access-Request message for user 'user01' to the Radius server and will expect Access-Accept or Access-Reject to consider the connection to the RADIUS sustainable.

The username user for that purpose is hardcoded to the FortiOS and cannot be altered.