Abstract: Dynamic routing protocol is the difficulty and focus in the teaching of computer network infrastructure. The GNS3 is excellent and graphical network virtualization software operating in multi-platform network virtualization software. By GNS3 application in strong conceptual and practical computer network course teaching, and by combining with powerful Wireshark (data package analysis software), RIP protocol was studied in-depth in principle and application. We received a good teaching effect and teaching evaluation.