In the Guest method, users are not saved in an LDAP directory. Instead, they are associated with accounts automatically generated by the firewall with lifetimes that match guest users' authentication durations.
These accounts take on the form of a random character string with a "guest_" prefix.
If customized first name, last name and email address fields, for example, have been defined in the authentication profile, the values entered in these fields will make it possible to associate the real user with the virtual user.
In the firewall's web administration interface, look up logs (Authentication, Network connections and Filter) and reports in order to check that the implemented configuration is running as planned.
The Authentication log indicates the guest_xxxx name assigned by the firewall (User column), the host's source IP address, the method ("Guest") and the value of any additional fields if the user has filled them in (Message column).