You do not need an internet connection. You can run a local server using minilogin. You can run both client and server on a fairly minimal system. I ran a server w\ +25-30 population at one time on an athlon xp 1.8ghz 768megs. And I was able to log into the server locally without many problems.
Just have to reboot more often ;p
Read techguy's guide.
http://techguynky.com/Documents/Guide.pdf