Use server 2003 vpn on SBS Network

Normally you would just give the 2003 server active directory so it could authenticate users for it's vpn, however, if you are in a situation where you can't do that and want to use the Radius of SBS 2003 for a 2003 server remote access, then assuming you have IAS already setup on the SBS 2003. On your Server 2003 Routing and remote access, right-click the server and choose properties.  

Now on the security tab, choose Radius as the Authentication provider - click configure and put in the correct Radius settings.

Quick fix if you know where to look.

Normally I wouldn't post about this, but it took me half an hour of research and eventually just spending 15 minutes to figure it out on my own.