usename + password + MAC address

Hi all, On a Radius version 2.x, we would like to tie an user to a MAC address. The auth key would then be the username, password and MAC address (Calling Station ID). Where is the right place to do that? - On the freeRadius? (any hint, please?) - In the PGSQL behind? (using some FUNCTION, I have an idea of that) Thank you. -- Architecte Informatique chez Blueline/Gulfsat: Administration Systeme, Recherche & Developpement +261 34 29 155 34