Can I install the ISA firewall client on the ISA Server?

A. No, the Internet Security and Acceleration (ISA) Server 2000 doesn't support this configuration (although I've seen it work). Granted, this approach seems like the logical solution to the problem that all the ISA clients can see the Internet resources via the ISA Server but the ISA Server itself can't view anything. However, you shouldn't install the client on the server.

Instead, to grant the ISA Server access to resources, you must configure packet filters. For example, if you want to allow outbound Web server access, create a packet filter that allows outbound requests to TCP 80.