5. The Support Machines
In theory, you should need no other computers than the mock mainframe and
whatever you use as terminals. In practice, you'll probably want additional
machines for specific tasks. Usually this will be because of security, not
performance.
For example, let's assume you have a network with a dial-up connection to
the Internet for email and browsing. Of course you could put all the hard-
and software required on the mock mainframe and not see much of a
performance hit (in fact, if your network is slow, it might even be
faster). But that puts your most valuable computer right where everybody
who is on the Internet — which increasingly means anybody on the planet —
can attack it.
For better security, put a machine between the mock mainframe and the
outside world. Make sure this Guardian machine is not only heavily
fortified, but also expendable, so if it is taken over by the forces of
evil or compromised in any other way, you won't lose anything valuable. To
lock down the network in an emergency, all you have to do now is to
physically turn off the power of the guardian machine (assuming this is the
only entry point to your local net). This can be very useful if you can't
sit down and go though security measures the moment you see a problem,
because, say, your boss at the burger grill just does not realize how
important that dorm network is and unfeelingly insists you show up on time
to flip the meat.
Other functions you might want to isolate on different machines are web- or
other servers on your net that people from the Internet can access. You can
also have a support machine tend your Linux Terminals (a Terminal Mother)
or to burn CDs (a Burner).