This chapter introduces a brand new concept in Microsoft ISA Server 2004: multinetworking. Multinetworking is a way to define many different types of networks (such as internal, perimeter, external, and so on), control the access between those networks, and truly segment the traffic on the networks you manage in the way that you want. In Microsoft ISA Server 2000, you might recall that there was a Local Address Table (LAT) that defined your internal network segments. Anything not in the LAT was considered external. The multinetworking functionality of ISA Server 2004 completely alters the way you, as an ISA administrator, will set up and configure your firewall.
The basic premise is that you first need to define your networks. You can then group those networks into network sets. Lastly, you define how the networks communicate with one another using network rules. Each of the networks you create is isolated from the others, so the communication is dependent on your configuration of the firewall access policy. This chapter focuses on the following topics:
Web and firewall chaining