With the increase and diversification of network users, the scale of the inter-domain routing system is becoming larger and larger. Cascading failure analysis and modeling are of great significance to improve the security of inter-domain routing networks. To solve the problem that the propagation principle of cascading failure does not conform to reality, a Cascading Failure Model for inter-domain routing systems with the Recovery Feedback Mechanism (CFM-RFM) is proposed in this paper. CFM-RFM comprehensively considers the main factors that cause cascading failure. Based on two types of update message propagation mechanism and traffic redistribution, it simulates the cascading failure process. We found that under the action of the recovery feedback mechanism, the cascading failure process was accelerated, and the network did not quickly return to normal, but was rather quickly and extensively paralyzed. The average attack cost can be reduced by 38.1% when the network suffers the same damage.

Inter-domain routing systems is an important complex network in the Internet. Research on the vulnerability of inter-domain routing network nodes is of great support to the stable operation of the Internet. For the problem of node vulnerability, we proposed a method for identifying key nodes in inter-domain routing systems based on cascading failures (IKN-CF). Firstly, we analyzed the topology of inter-domain routing network and proposed an optimal valid path discovery algorithm considering business relationships. Then, the reason and propagation mechanism of cascading failure in the inter-domain routing network were analyzed, and we proposed two cascading indicators, which can approximate the impact of node failure on the network. After that, we established a key node identification model based on improved entropy weight TOPSIS (EWT), and the key node sequence in the network can be obtained through EWT calculation. We compared the existing three methods in two real inter-domain routing networks. The results indicate that the ranking results of IKN-CF are high accuracy, strong stability, and wide applicability. The accuracy of the top 100 nodes of the ranking result can reach 83.6%, which is at least 12.8% higher than the average accuracy of the existing three methods.

Inter-domain routing systems are important complex networks on the Internet. It has been paralyzed several times in recent years. The researchers pay close attention to the damage strategy of inter-domain routing systems and think it is related to the attacker's behavior. The key to the damage strategy is knowing how to select the optimal attack node group. In the process of selecting nodes, the existing research seldom considers the attack cost, and there are some problems, such as an unreasonable definition of attack cost and an unclear optimization effect. To solve the above problems, we designed an algorithm to generate damage strategies for inter-domain routing systems based on multi-objective optimization (PMT). We transformed the damage strategy problem into a double-objective optimization problem and defined the attack cost related to the degree of nonlinearity. In PMT, we proposed an initialization strategy based on a network partition and a node replacement strategy based on partition search. Compared with the existing five algorithms, the experimental results proved the effectiveness and accuracy of PMT.