You can configure the Smoothwall to use a remote authentication dial in user service (RADIUS) as an authentication service.
Normalizing Usernames in a RADIUS Configuration
The Smoothwall Filter and Firewall is unable to differentiate between an unknown user, and a valid user that has entered an incorrect password in a RADIUS configuration, as RADIUS servers need a valid password to be able to provide user information to the Smoothwall. If Normalize usernames is turned on (see our help topic, Configuring global authentication settings), the Smoothwall assumes the supplied username is valid and stores it in a lower-case format.
Accounting
An alternative RADIUS connection to use is the RADIUS Accounting option. This directory server connection is a passive connection, where the RADIUS server connects to the Smoothwall and just sends user accounting information. No messages are sent to the RADIUS server from the Smoothwall.
If user group information isn't sent as part of the RADIUS accounting packet, the Smoothwall uses the group information from the next directory server listed in the Directories table. Because of this, you must make sure that your directories are listed in the correct order, with the RADIUS entry directly before the directory containing the group information. If there are no other directories listed, the Smoothwall places all users in the Default users group.