Microsoft Internet Security and Acceleration Server 2004 SDK

About ISA Server Clients

ISA Server supports three types of clients:

Firewall clients are client computers that have Firewall Client installed and enabled.
Secure network address translation (SecureNAT) clients are client computers that do not have Firewall Client installed.
Web proxy clients are any client Web application configured to use ISA Server.

The following table compares the ISA Server clients.

Feature	SecureNAT client	Firewall client	Web proxy client
Installation required	Some network configuration changes are required	Yes	No, requires Web browser configuration
Operating system support	Any operating system that supports Transmission Control Protocol/Internet Protocol (TCP/IP)	Only Windows platforms	All platforms, but by way of Web application
Protocol support	Requires application filters for multi-connection protocols	All Winsock applications	Hypertext Transfer Protocol (HTTP), Secure HTTP (HTTPS), File Transfer Protocol (FTP), and Gopher
User-level authentication	No	Yes	Yes
Server applications	No configuration or installation required	Requires configuration file	N/A

Firewall client computers and SecureNAT client computers may also be Web proxy clients. If the Web application on the computer is configured explicitly to use the ISA Server, then all Web requests (HTTP, FTP, HTTPS, and Gopher) are sent directly to the Web proxy. All other requests are handled first by the Firewall service.

This section contains the following topics: