Extending the MySQL Functionality
Now that the basic MySQL support has been installed, configured, and tested, this section will help you enable more advanced features that extend the capabilities of the FreeRADIUS/MySQL combination.
Realm support
It is fairly simple to get realm support when using the database model for FreeRADIUS authentication. You need to enable the stripped usernames feature of FreeRADIUS in order for realm support to work. If not, FreeRADIUS passes the full value of the username attribute—jhassell@raleighinternet, for example—and, in this case, the database is not set up to support that. By enabling stripped usernames, FreeRADIUS deletes the @raleighinternet portion of the username, which allows the query against the database to proceed successfully.
To enable the stripped user name functionality:
Open /etc/raddb/sql.conf in your favorite text editor.
Locate the section called query config: username.
Uncomment the line sql_user_name = "%{Stripped-User-Name:-%{User-Name:-none}}";
Comment out the line sql_user_name = "%{User-Name}"
The realm functionality should work as expected. If you, in fact, do need to distinguish users in your database (only if your usernames are not unique across all realms), then edit the user entries inside the authentication database and disable the realm-stripping feature.
Redundancy with MySQL
To introduce a level of fault tolerance and added data integrity security, you may want to consider having two machines running MySQL that replicate ...