Application Filters

Application filters are extensions of the Microsoft® Firewall service. These filters register for and process Firewall service events. By exposing its COM interfaces to developers, ISA Server allows them to extend its security and functionality. Developers can use these interfaces to extend the security and access control for the Firewall service, and to create protocol-specific application filters. These can share the architecture, access control, and administration of the Firewall service. Use of these interfaces is described in Developing Application Filters. Specifically, the interfaces allow a filter to:

• Receive notifications of special events; for example, when a user connects to a certain remote port.
• Allow or deny user access to certain operations; for example, binding to a particular port.
• Examine and possibly modify data that flows through the firewall; for example, to perform virus checking.
• Initiate network operations (proactive caching) through dynamic IP packet filtering.
• Integrate seamlessly with ISA Server Management.

See Also

Developing Application Filters, Filter Interfaces