A mechanism that enables flexible expansion of proxy firewall services is disclosed. In accordance with the present invention, the firewall system can be configured to include a dispatch host computer and one or more load host computers. Proxy firewall services can be provided by proxy applications that reside on either the dispatch host computer and/or the load host computers. In one embodiment, a load host computer can be configured to support multiple proxy applications. In other embodiments, a load host computer can be dedicated to a single resource intensive application. In this framework, a network administrator can flexibly decide how to accommodate the demand for proxy firewall services. Load hosts can be added or removed from the firewall system without disrupting ongoing security services. In one embodiment, this feature is enabled through the inclusion of a configuration file on the dispatch host computer that stores information relating to the load host computers in the firewall system.