A new teaching mode for network design is proposed, which is based on simulating the process of network engineering. The teaching mode can help students to master the necessary designing skills of both small Enterprise LANs and WANs. By simulating the upgrade of networks of a cultural center, ,the details of design processes are exhibited, such as collecting customer requirements, translating those requirements into equipment and protocol needs, and creating a network topology which addresses the needs of the customer. Students are familiarized with how to create and implement a design proposal for a virtual customer. This kind of teaching mode prepares the students with the skills required for entrylevel Pre-Sales Support and entry-level Network Design jobs.