This performs a network discovery using simple pings
$ nmap -sP 192.168.1.0/24
Starting Nmap 6.46 ( http://nmap.org ) at 2014-04-30 20:22 BST
Nmap scan report for orinoco.config (192.168.1.67)
Host is up (0.00050s latency).
Nmap scan report for tobermory.config (192.168.1.72)
Host is up (0.00038s latency).
Nmap scan report for bebox.config (192.168.1.254)
Host is up (0.0024s latency).
Nmap done: 256 IP addresses (3 hosts up) scanned in 6.33 seconds