The status of machines on the local network can sometimes be found by typing
uptime
The display that appears will list the local host computers, whether they are up (running) or down and how long they have been in that state. The number of users is often the number of non-system processes and so is not really reliable. The load figures are the average saturation over the last 1, 5 and 10 minutes respectively.
Where ruptime fails, a program called ping can tell you
whether a particular machine is up and running, or not. ping
often lives in /etc. For example
ping linux.ox.ac.uk
typed at a machine on the same network, should report on this machine's status.