How to set servers file in radiusclient-ng install ?

hi friend, i see the tutorial in the url http://svn.dd-wrt.com:8000/dd-wrt/browser/src/router/asterisk/doc/radius.txt it says : " Each line contains hostname of a RADIUS server and shared secret used in communication with that server. " is that say i must set the hostname of a RADIUS server, could i set IP addr of the RADIUS server? Thanks! -- Regards, Sucan