Once your Radius server is set up as mentioned above, you will need to configure your wireless settings as shown in figure 3-19 on page 15 in the document at
http://downloads.linksysbycisco.com/downloads/WRT54GS-EU_v6_UG_efgn,0.pdf You will replace the radius server IP with the one you just set up and the port with 1812 if the IAS is not on a domain controller. If it is the port is 2012. you will need to input the key you set when creating the client record in IAS. That should be it. that is the two components. If you run into any questions, please let me know.