  In recent years, the emerged network worms and attacks have distributive
characteristic, which can spread globally in a very short time. Security
management crossing network to co-defense network-wide attacks and improve
efficiency of security administration is urgently needed. This paper proposes a
hierarchical distributed network security management system (HD-NSMS), which
can centrally manage security across networks. First describes the system in
macrostructure and microstructure; then discusses three key problems when
building HD-NSMS: device model, alert mechanism and emergency response
mechanism; at last, describes the implementation of HD-NSMS. The paper is
valuable for implementing NSMS in that it derives from a practical network
security management system (NSMS).
