It can often be the case that you need to scan the network to find a particular machine that has received a different IP address under a DHCP (Dynamic Host Configuration Protocol) allocation.

The easiest way to do this under Linux is to use:

Where I am scanning in the range of DHCP allocation that I have allocated on my network. My minimum address is 100 and the maximum is 255 and my subnet is 192.168.1.*. This does a simple “TCP Connect Scan”, where it checks for open ports on the machine – this allows you to determine which machines and which services are available. We need to happen fairly quickly, so the options are:

-T4 sets a fast timing template (T5 is as fast as possible)

-F is Fast mode that scans fewer ports than the default scan

And the range is set by If you do not have nmap installed you can install it on Ubuntu using “sudo apt-get install nmap”