Not gunna go to in-depth into what the company I work for does, but one thing we do, do is manage customer's firewalls for them... from what I am to understand nearly everybody in technical support department has had a trial by fire from those damned things.
I consulted for a company that blamed everything on Active Directory. The Firewall was a big issue. From time to time they firewall people would block the port that Windows 8 Server needed to get it's licensing from. If it didn't find it, it would ask you to activate it. We would request the port be open and it would work for a few months, if the firewall team even responded, then it would be blocked again.
I've seen managers who take a person they would like to get rid of and make him the network admin. After a few weeks and a couple of virus outbreaks, everybody hates him enough in order to fire him by popular demand.