Granting or Denying Access to a Group of Computers (IIS 6.0)
A group of computers can be either denied or granted access based upon their network ID and a subnet mask.
For example, if the host computer has an IP address of 172.16.16.1 and a subnet mask of 255.255.0.0, all of the computers in that subnet would have IP addresses that began with 172.16. To select all of the computers in the subnet, enter 172.16.16.1 in the Network ID box and 255.255.0.0 in the Subnet Mask box.
You must be a member of the Administrators group on the local computer to perform the following procedure or procedures. As a security best practice, log on to your computer by using an account that is not in the Administrators group, and then use the runas command to run IIS Manager as an administrator. At a command prompt, type runas /user:Administrative_AccountName "mmc %systemroot%\system32\inetsrv\iis.msc".
To grant or deny access to a group of computers
Configuration settings made at the Web or FTP Sites level are inherited by all of the Web or FTP sites on the server. You can override inheritance by configuring the individual site or site element.