Introduction

Planning your ISA Server installation before actually performing it is absolutely critical. As with any firewall, the amount of thought and analysis you put into your design will help optimize ISA performance and will minimize the chance of making a substantial error that will adversely affect your security or access schemes.

All traffic that moves between the Internet and your internal network should move through a firewall, which is your ISA server. It is the job of the bastion host to ensure that all packets sent to and received from the Internet are evaluated and assessed for their relevance and safety.

The ISA server is a firewall because it provides the demarcation point between a trusted and untrusted network. Moreover, the ISA server can provide DMZ services through additional network interfaces. Because of this, it is critical to make sure that the ISA server is set up as securely as possible.

ISA Deployment: Planning and Designing Issues

When you decide to put together an ISA Server solution for your organization, you should plan ahead. ISA Server is an integral part of your security configuration scheme, and you do not want to merely install the server and hope that everything works out right. Carpenters have an old saying: "Measure twice, cut once." If you thoroughly map out your design, you'll avoid pitfalls in your deployment and further down the line.

In this section, we focus on planning and design issues as they relate to the installation of ISA Server. The...