Does anyone no of any networks running on Linux servers?

[Kevin]

I have been a student of technology for almost a year and a half now at
Heald College.  I recently began experimenting with RedHat 7.0.  The
things I have been discovering make it worth the trouble of learning a
whole new world besides the M$ jive thats crammed into my head at Heald. 
To get to the point, my Networking Essentials instructor has given us an
assignment to find an admistrator who will let us visit his/her network
and answer some questions.  I thought that I would do something that I
know no one in my class will do.  I want to visit a Linux based network
and learn a little more about Linux at the same time.  Any open source
platform would actually work, but I know that everyone in my class will be
visiting M$ or Novell networks.  I, of course, want to be different and
introduce the Penguin to my misguided classmates.  Thanks for any help you
can provide.