Sticky ports are one of the network admin's best friends and worst headaches. They allow you to set up your network so that each port on a switch only permits one (or a number that you specify) computer to connect on that port by locking it to a particular MAC address. If any other computer plugs into that port, the port shuts down and you receive a call that they can't connect anymore. If you were the one that originally ran all the network connections then this isn't a big issue, and likewise if it is a predictable pattern then it also isn't an issue. However if you're working in a hand-me-down network where chaos is the norm then you might end up spending a while toning out exactly what they are connecting to.