Using nmap network tool is easy to discover other live hosts on the lan.
If your ip address is something like this: 192.168.2.8 then the only thing you have to do to discover other hosts on the network is to type in your terminal the command:
nmap -sP 192.168.2.0/24 and you get something like this:
Nmap scan report for 192.168.2.8
Host is up (0.000092s latency).
Nmap scan report for 192.168.2.100
Host is up (0.00071s latency).
Nmap scan report for 192.168.2.11
Host is up (0.00063s latency).
Nmap done: 256 IP addresses (3 hosts up) scanned in 2.51 seconds