Detection of SDN Flow Rule Conflicts Based on Knowledge Graph

Software-Defined Network (SDN) separates the control plane and data plane to provide a more flexible network. In that case, switches only need to follow the flow rules that controllers send. However, when conflicts between policies in applications happen, the flowrules they sendmay conflict too, then the behavior of switches may not be as expected. Moreover, the process of pipeline with multiple tables has made the match of flow rules more flexible but complicated. Therefore, precisely and easily detecting flow rule conflicts in one table and among multiple tables is crucial. Nowadays, knowledge graph has become a hot spot, with a good representation on entities and complex network relations. Besides, it has a reasoning ability, which can discover new relations between entities. So, we construct an SDN flow rule conflicts detection knowledge graph to store the network information including flow rules, then set up production rules according to the definition of flow rule conflicts with conflicts in one table and conflicts among multiple tables. The production rules are easy to read and modify. The result shows that the conflicts can be detected correctly with a clear reasoning process by production rules.