My company just acquired one of our competitors. I am going through this other company's data center and it is killing me... it is really helpful that their network admin quit and is not taking phone calls.
They have at my current count 35 windows server instances for their LAN. They have dedicated domain controllers, dedicated DNS servers, dedicated WINS servers (seriously?), dedicated DHCP servers, dedicated file servers, dedicated print servers, dedicated IAS servers, and so on and so forth. I even found an old half-life server! I haven't even inventoried all the web site specific installs which are at least 10 more. Most of these are virtual machines on top of VMWare. This is a small consulting company with 9 employees plus their hosting agreements. I'm worried about licensing violations... I hope our owner and the business attorney have their ducks in a row.
On top of that there are 47 different vlans/subnets in place. In many cases I haven't figured out what they are for, there's nothing in them.
What I think happened is somebody just got their CCNA and went completely overboard on the network design throwing KISS out the window. At least they threw a lot of cash at really expensive Cisco hardware and a nice EMC SAN so when I do my redesign I have a great starting point.
My favorite part is they have billed themselves as a high end web host with all this high end equipment that is overly complicated, but have no internal backups of data, and one Internet connection through a mom and pop type ISP.
