LDoS attack real-time detection and mitigation method of FIN

The invention discloses an LDoS attack real-time detection and alleviation method of an FIN, and belongs to the field of network security. The method comprises the following steps: collecting traffic characteristic data collected in a programmable switch, wherein the characteristics comprise TCP traffic distribution entropy and TCP data packet number; secondly, decimal part estimation of a result in approximate logarithm operation is achieved based on fixed-length prefix matching, approximate exponential operation is achieved based on generalized binomial expansion, division operation is achieved based on the decimal part estimation and the exponential operation, and the defect of a programmable switch instruction is overcome; training an LDoS attack detection model by using the collected feature data, and realizing deployment of the LDoS attack detection model in the programmable switch based on deviation standardization of longest prefix matching, activation function and parallelization vector inner product