Configuring ISA Server Clients

As I describe in "Authenticate Internet Access with ISA Server," June 2003, http://www.secadministrator.com, InstantDoc ID 38773, Microsoft Internet Security and Acceleration (ISA) Server 2000 supports three methods for providing controlled Internet access for internal clients: Secure Network Address Translation (SecureNAT), Web proxy, and firewall. SecureNAT doesn't require any configuration on the client computer other than setting the default gateway of the client machine to be the ISA Server machine, a task that's usually automated by using a DHCP server. (In a subnetted environment, the ISA Server system doesn't need to be the default gateway, but the default route needs to go through the ISA Server machine.) However, SecureNAT access doesn't use username-based authentication, so you might prefer the Web proxy and firewall methods, which provide user-specific access control.

The Web proxy method requires setting one client browser option, and the firewall method requires Firewall Client software installation. Although the Web proxy and firewall configuration might not look like a chore at first, remote clients and maintaining client configurations as you add and remove ISA servers complicate the task for administrators. Fortunately, you can easily set up the ISA Server Web Proxy service and Firewall Server so that configuration is automated for users. . . .