You have one campus, which contains 2,000 PCs, and each edge switch will contain 25 to 40 PCs. Based on this layout, which design model should be used?

Based on the layout of your network, the collapsed core model is the most appropriate model to design. If at a later time other campuses are joined to the network, the core layer can be added. The three-tier model is better situated for a network with multiple campuses. DOD model is a term used when referring to the layers of the OSI model in a macro model. Access model is not a term used with switching and routing design.