Abstract. Static assignment of ip addresses or identifiers can be exploited by an adversary to attack a network. However, existing dynamic ip address assignment approaches suffer from two limitations, namely: participation of terminals in the assignment and inadequate network server management. Thus, in this paper, we propose an overall-transparent dynamic identifier-mapping mechanism to manage the identifier of network nodes to defend against scanning in the smart identifier network. We establish the selection and allocation constraints. The non-repetition probability and cover cycle allow us to evaluate the defense efficiency against scanning. Simulation results and theoretical analysis show that the proposed method effectively reduces the detection probability of routing identifiers.