If you want to which all IP addresses are active in your local LAN then just install nmap on your linux/ubuntu and then execute following command.
I think we can do alot of more just finding out active IP addresses in local LAN.. you can explore futher options.
nmap -v -sP 192.168.116.0/24
( in my case our local IP address has IP addresses starting from 192.168.116.1 to 192.168.116.255 )
