ISA Server 2004 Configuration Guide 4
Practice configuring the ISA Server 2004 firewall
The firewall is your first line of defense against Internet attackers. A misconfigured firewall can
potentially allow Internet attacks access to your network. For this reason, it’s very important
that you understand how to configure the firewall for secure Internet access.
By default, the ISA Server 2004 prevents all traffic from moving through the firewall. This is a
secure configuration because the firewall must be explicitly configured to allow network traffic
through it. However, this level of security can be frustrating when you want to get connected
to the Internet as quickly as possible.
We strongly encourage you to create a test lab and perform each of the walkthroughs in this
guide. You will learn how to configure the ISA Server 2004 firewall correctly and become
familiar with the ISA Server 2004’s configuration interface. You can make mistakes in the
practice lab and not worry about attackers taking control of machines on your network. On the
lab network, you’ll be able to learn from your mistakes instead of suffering from them.
