Date: 2013dec2 OS: Linux Product: nmap Keywords: network, net, scan, map Q. How do I scan all the computers on my LAN? A. Like this:

nmap 192.168.40.0/24

Change the IP-address to suit your LAN. (Assuming you're using that range of IP-Addresses) This will look at:

192.168.40.0 192.168.40.1 192.168.40.2 ... 192.168.40.254 192.168.40.255

256 computers. A cool trick of nmap... It can tell you the manufacturer of a device on your LAN based on its MAC address. So if you want find the IP-address of your Cisco voip box? Scan the LAN with nmap. If you run its as ROOT with -sn you can get the MAC access:

nmap -sn 192.168.1.0/24