|Microsoft Internet Security and Acceleration Server 2004 SDK|
Client computers that do not have Firewall client software are secure network address translation (SecureNAT) clients. SecureNAT clients can benefit from many of the features of ISA Server. This includes most access control features, with the exception of high-level protocol support and user-level authentication.
Although SecureNAT clients do not require special software, you should configure the default gateway so that all traffic destined to the Internet is sent by way of ISA Server, either directly or indirectly, through a router. You can configure clients either by using the DHCP service or manually.
Since requests from SecureNAT clients are essentially handled by the Firewall service, SecureNAT clients benefit from the following security features:
ISA Server extends the Windows NAT functionality by enforcing ISA Server policy for SecureNAT clients. In other words, all ISA Server rules can be applied to SecureNAT clients, despite the fact that Windows NAT does not have an inherent authentication mechanism. (Policies regarding protocol usage, destination, and content type are also applied to SecureNAT clients.)
As with Firewall clients, SecureNAT clients can also actually be servers, such as mail servers, which publish information to the Internet. You configure server publishing rules to publish servers as SecureNAT clients.
SecureNAT clients are not supported in cache mode.