Introduction
An ISA Server 2004 client is a machine that connects to a resource by going through the ISA Server 2004 firewall. In general, the ISA Server 2004 client is located on an Internal or perimeter network segment and connects to the Internet through the ISA Server 2004 firewall.
There are three ISA Server 2004 client types:
•The SecureNAT client
•The Web Proxy client
•The Firewall client
A SecureNAT client is a machine configured with a default gateway that can route Internet- bound requests through the ISA Server 2004 firewall. If the SecureNAT client is on a network directly connected to the ISA Server 2004 firewall, the default gateway of the SecureNAT client is the IP address of the network interface on the ISA Server 2004 firewall connected to that segment. If the SecureNAT client is located on a network segment that is remote from the ISA Server 2004 firewall, the SecureNAT client is configured with an IP address of a router that routes Internet bound requests through the ISA Server 2004 firewall machine.
A Web Proxy client is a machine whose browser is configured to use the ISA Server 2004 firewall as its Web Proxy server. The Web browser can be configured to use the IP address of the ISA Server 2004 firewall as its Web Proxy server, or it can be set to use the ISA Server 2004 firewall’s Web Proxy autoconfiguration script. The autoconfiguration script confers a higher level of flexibility in controlling how Web Proxy clients connect to the Internet. User names are recorded in the Web Proxy logs when the machine is configured as a Web Proxy client.
A Firewall client is a machine that has the Firewall client software installed. The Firewall client software intercepts all Winsock application requests (typically, all TCP and UDP requests) and forwards them directly to the Firewall service on the ISA Server 2004 firewall. User names are automatically entered into the Firewall service log when the Firewall client machine connects to the Internet through the ISA Server 2004 firewall.
The following table summarizes the features provided by each client type.
Table 1: ISA Server 2004 Client Types and Features
Feature
Installation
Operating system support
Protocol support
SecureNAT client | Firewall client | Web Proxy client |
Yes, requires some network | Yes | No, requires Web |
configuration changes |
| browser configuration |
Any operating system that | Only Windows | All platforms, but by way |
supports TCP/IP | platforms | of a Web application |
Application filters for multi- | All Winsock | HTTP, Secure HTTP |
connection protocols | applications | (HTTPS), and FTP |
Yes, for VPN clients only | Yes | Yes |
We will discuss the following procedures in this ISA Server 2004 Configuration Guide document:
•Configuring the ISA Server 2004 SecureNAT client
ISA Server 2004 Configuration Guide | 114 |
