Network topology confusion method and system for defending link flooding attack

The invention relates to a network topology confusion method and system for defending link flooding attacks, and the method comprises the steps: S1, collecting routing paths # imgabs5 # of a node set # imgabs0 #, a network link set # imgabs1 #, a network link bandwidth # imgabs2 #, a network flow set # imgabs3 # and a network flow set # imgabs4 # of a network to be protected, S2, calculating the traffic density of each # imgabs6 #, and if the traffic density is higher than the traffic density of # imgabs7 #, adding a key link set # imgabs8 #; s3, if the # imgabs9 # contains the key link, adding the # imgabs10 # into the to-be-confused stream set; s4, splitting the to-be-confused stream set into an invariant stream and an operation stream; s5, splitting a key link of the operation flow into two virtual links, and obtaining a virtual routing path; s6, randomly selecting a virtual link and calculating the traffic density of the virtual link, and if the traffic density is lower than a threshold value, adding a pl