Abstract: Due to the significant effect on the discovery result,probing sources selection plays a vital role in unauthori-zed target network topology discovery．Thus,properly selecting a fixed number of probing sources would dramatically increase the coverage of discovered network．For this,a novel indicator,GDS(General Dispersity of Sources),depicting the logic distance of a set of probing sources was designed．Meanwhile,experiment shows that probing source set with a larger GDS tends to get a wider topology coverage．Subsequently,maximum GDS selection which represents screening the probing source set with maximum GDS out of the whole probing source collection was proposed．Moreover,the HGSAA (Hybrid Genetic Simulated Annealing Algorithm) often used in the field of power grid formulation was tailed-made to accurately screen out the probing source set with maximum GDS．On the basis of experiments,it is demonstrated the probing source set selected by the method based on maximum GDS selection results in more router interfaces and links compared with the ones of SDIS selection,low degree selection and random selection.

Key words: Network topology discovery,Probing source,Logic distance,General dispersity of sources,Anchor point set,Hybrid genetic simulated annealing algorithm