ers belong near the users that they serve, or in a farm near the core? Where servers belong in your network depends on how your network is designed, and often on the type of server in question. Some servers should be in the core. Centrally locating email servers, for instance, makes sense. Other servers should be closer to the users they serve. For example, in a campus network, it would not make sense to put ac- counting servers in the core if the entire Accounting department is located in one building. Then again, there may not be space in each building for servers. A lot depends on the layout of your network, too. Many companies these days are building completely flat networks, with the core/distribution/access model being com- pletely collapsed into a single pair of large switches, such as Cisco 6509s. In this case, everything is connected to the same switches, making the argument moot. Another scenario I've seen that lends itself to this type of design is the segmented building. One project I worked on involved redesigning the network for a major Chapter 35: Designing Networks stadium. The stadium was divided into four segments, each of which had its own in- frastructure room (closet). The users' cables were run to these closets, and the closets were linked together with fiber. Figure 35-9 shows an example of a collapsed-core network without a distribution layer. Internet Server farm 00000 Users, printers, etc. Figure 35-9. Collapsed-core network without a distribution layer Collapsed core-no distribution or access A very popular design in companies that are contained within a single building is the collapsed network, where there are only core switches. A company with hundreds of employees that are all in a single location can often manage to have its computer room central to the environment. As long as the Ethernet runs can remain within the distance limitations of the cabling in use, all runs can be home runs back to the core switches. A pair of high-density, high-availability switches like Cisco 6509s can 