1. Clients to query the rwho server The rwho command produces output similar to who, but for all machines on the local network. If no report has been received from a machine for 11 minutes then rwho assumes the machine is down, and does not report users last known to be logged into that machine. The ruptime command gives a status line like uptime for each machine on the local network; these are formed from packets broadcast by each host on the network once a minute. From Debian 3.0r0 APT

2. The rwho command displays output similar to the output of the who command (it shows who is logged in) for all machines on the local network running the rwho daemon. Install the rwho command if you need to keep track of the users whoare logged in to your local network. From Mandrake 9.0 RPM