How to...
1. Install IAS http://technet2.microsoft.com/WindowsServer/en/library/9a2a064f-a298-402...
2. Manage a remote IAS server http://technet2.microsoft.com/WindowsServer/en/library/5a1cc144-4386-440...
3. Copy the IAS configuration to another server http://technet2.microsoft.com/WindowsServer/en/library/ef7c938e-e714-41e...
4. Enable the IAS server to read user accounts in Active Directory http://technet2.microsoft.com/WindowsServer/en/library/71b2aa02-5746-413...
5. Start or stop IAS http://technet2.microsoft.com/WindowsServer/en/library/18ce1c5c-b7c0-43e...
6. Configure IAS Properties http://technet2.microsoft.com/WindowsServer/en/library/baf48c9a-2765-4d9...
7. Configure RADIUS Clients http://technet2.microsoft.com/WindowsServer/en/library/33abd949-fa36-44f...
8. Configure Remote Access Policies http://technet2.microsoft.com/WindowsServer/en/library/bf963b52-65e1-464...
9. Configure Connection Request Processing http://technet2.microsoft.com/WindowsServer/en/library/894f7f2d-f7f4-4cf...
10. Configure Logging for User Authentication and Accounting http://technet2.microsoft.com/WindowsServer/en/library/33a7945d-7b0e-4ec...

Note

You can configure IAS in Windows Server 2003, Standard Edition, with a maximum of 50 RADIUS clients and a maximum of 2 remote RADIUS server groups. You can define a RADIUS client using a fully qualified domain name or an IP address, but you cannot define groups of RADIUS clients by specifying an IP address range. If the fully qualified domain name of a RADIUS client resolves to multiple IP addresses, the IAS server uses the first IP address returned in the DNS query. With IAS in Windows Server 2003, Enterprise Edition, and Windows Server 2003, Datacenter Edition, you can configure an unlimited number of RADIUS clients and remote RADIUS server groups. In addition, you can configure RADIUS clients by specifying an IP address range.

Source: http://technet2.microsoft.com/windowsserver/en/library/d98eb914-258c-4f0...