The rwho command produces output similar to who(1), but for all machines
on your network. If no report has been received from a machine for 5 minutes, rwho assumes the machine is down, and does not report users last known to be logged into that machine.
If a user has not typed to the system for a minute or more, rwho reports this idle time. If a user has not typed to the system for an hour or more, the user is omitted from the
output of rwho unless the -a flag is given.
The directory /var/spool/rwho must exist on the host from which rwho is run.
This service takes up progressively more network bandwith as the number of hosts on the local net increases. For large networks, the cost becomes prohibitive.
The rwho service daemon, in.rwhod(1M),
must be enabled for this command to return useful results.