Microsoft ISA Server uses rules to determine the level of access allowed for Internet resources. Rules are also used to determine the level of external network client access to internal resources (through Web and server publishing rules) and resources contained on perimeter networks (through packet filters). Using the ISA Server rules, you can attain a high level of control over both inbound and outbound access.

ISA Server rules involved with outbound access are grouped into access policies. There are three categories of access policy:

• Site and content rules

• Protocol rules

• IP packet filters

Site and content rules are used to determine the sites (computers or domains) that can be accessed through the ISA server. They are also used to control the content that can be accessed via HTTP. A schedule can be applied to these rules that will assign the day and time when the rule is in effect. In order to access sites and content on the Internet, there must be a site and content rule that allows access. ISA Server includes a default site and content rule that allows access to all sites and all content at all times. You must create new site and content rules and disable the default to obtain more granular control.

Protocol rules determine the protocols that are available for both inbound and outbound access. Protocol rules will be used to determine outbound access, since you ll use publishing rules to determine inbound access policy, although both take...