Security Problem? I need some Information

I have just run into some static with the powers that be in my place of employment with respect to my use of Linux rather than Windows. I am connected to a University network. There is also an internal LAN that serves my school only. The other computers in this operation, all on Windows, are connected by default through the University network to that LAN. The fear is that my computer is a potential server for the LAN and therefore poses a security problem. I find this strange, but have no way of refuting it. Any help? Any references? Thanks dj tuchler