PRAETOR:Packet flow graph and dynamic spatio-temporal graph neural network-based flow table overflow attack detection method

The flow table overflow attack on SDN switches is considered to be a destructive attack in SDN. By exhausting the computing and storage resources of SDN switches, this attack severely disrupts the normal communication functions of SDN networks. Graph neural networks are now being employed to detect flow table overflow attacks in SDN. When a flow graph is constructed, flow features are commonly utilized as nodes to represent the characteristics of flow table overflow attacks. However, a graph solely relying on these nodes and attributes may not fully encompass all the nuances of the flow table overflow attack. Additionally, GNN model may be difficult in capturing the graph information between different flow graphs over time, thus decreasing the detection accuracy of packet flow graph. To address these issues, we introduce PRAETOR, a detection method for flow table overflow attacks that leverages a packet flow graph and a dynamic spatio-temporal graph neural network. More particularly, The PaFlo-Graph algorithm and the EGST model are introduced by PRAETOR. The PaFlo-Graph algorithm generates a packet flow graph for each flow. It utilizes packet information to construct the graph with more detail, thereby better reflecting the characteristics of flow table overflow attacks. The EGST model is a dynamic spatio-temporal graph convolutional network designed to detect flow table overflow attacks by analyzing packet flow graphs. Experiments were conducted under two network topologies, where we used tcpreplay to replay packets from the bigFlow dataset to simulate SDN network flow. We also employed sFlow to sample packet features. Based on the sampled data, two datasets were constructed, each containing 1,760 network flows. For each packet, eight key features were extracted to represent its characteristics. The evaluation metrics include TPR, TNR, accuracy, precision, recall, F1-score, confusion matrix, ROC curves, and PR curves. Experimental results show that the proposed PaFlo-Graph algorithm generates more detailed flow graphs compared to KNN and CRAM, resulting in an average improvement of 6.49% in accuracy and 8.7% in precision. Furthermore, the overall detection framework, PRAETOR, achieves detection accuracies of 99.66% and 99.44% on Topo1 and Topo2, respectively. The precision scores reach 99.32% and 99.72%, and the F1-scores are 99.57% and 100%, respectively, indicating superior detection performance compared to other methods.