Hi All; With your help i have managed to get Radius to do what i needed, thanks. Basically i have placed the following into the sites-available/default file on the authorize and accounting areas: if(User-Name){ if ("%{User-Name}" =~ /^(.{6,32})(@{1})(.{17})$/){ update request { User-Name := "%{1}" Realm := "%{3}" } } else { reject } } The Regex will allow: Usernames from 6 to 32 characters; Only one @ sign, and 32 Chars for the MAC Address Users without the @ MAC_ADDRESS will be dropped. With that REGEX true the Username and Realm are updated respectively on my MySQL DB. Next time anybody is around Windsor UK, let me know (email at the top) i'll treat you for a pint(s) of Stella and a Kebab Thanks again Lucio _________________________________________________________________ Tell us your greatest, weirdest and funniest Hotmail stories http://clk.atdmt.com/UKM/go/195013117/direct/01/