  Recent studies of attacks on complex networks suggest that small initial
breakdowns can lead to global cascades of overload failures in communication,
economic trading, and supply-transportation systems, considering the defense
methods is very important to reduce the huge damage. The propagation of
failures depends on the flow dynamics such as packet routing of physical
quantities and on the heterogeneous distribution of load or capacity in many
realistic networks which have topological properties of scale-free (SF) and
degree-degree correlations. We introduce a defense strategy based on emergent
rewirings between neighbors of the attacked node, and investigate the size of
cascade on SF networks with controllable correlations. We show the differences
of damaged size for the types of correlations and the effective range of
tolerance in the defense methods. They can be performed on the current wireless
communication or dynamic allocation technologies.
