A prevention-based network auditing system includes a plurality of heterogeneous information sources gathering information about the network. An audit server invokes the heterogeneous information sources via a uniform communications interface to gather information about the network, and converts the information gathered by the information sources into a normalized data format such as, for example, into XML (Extensible Markup Language). The converted information is then stored in an audit repository for security and regulatory policy assessment, network vulnerability analysis, report generation, and security improvement recommendations.