There are two utilities available in Linux and Unix that provide information about remote user logins. These are
rwho, which are backed up by corresponding daemons,
rwhod. These daemons share login information over the network allowing sysadmins to monitor login activity on different hosts.
Once the daemons are installed and running (
sudo apt-get install rwho rusers -y in Ubuntu,
yum install rwho rusers in Fedora and etc.) at different hosts across the network, you can use several tools to get login information about all of these hosts. One of them is rwho that is the remote and network-enabled version of the well known who tool.
[email protected]:~$ rwho
tesadmin tes1000_v203_1322_tst0:pts/1 Oct 24 10:25
viper viper-laptop:pts/0 Oct 24 10:24
viper viper-laptop:pts/1 Oct 24 10:26 :01
viper viper-laptop:pts/2 Oct 24 10:25
viper viper-laptop:tty7 Oct 24 09:11
Another one is rusers tool that broadcasts over the network for the
rusersd daemon on the other hosts to return the information about the users currently logged in:
[email protected]:~$ rusers
Sending broadcast for rusersd protocol version 3...
viper-laptop. viper viper viper viper
Another tool available when rwhod is running is ruptime that outputs the loading and uptime information for all servers running rwhod in the LAN.
[email protected]:~$ ruptime
tes1000_v203 up 14+19:00, 1 user, load 0.59, 0.47, 0.46
viper-laptop up 1:39, 4 users, load 0.40, 0.52, 0.45
This is really nice tool to monitor status of servers without need to log in to them.
You can read more information about these tools and related ones here (IBM’s doc).