Installing Nmap

Nmap is designed to allow the scanning of networks in order to determine which hosts are up and what services are they offering. Nmap supports a large number of scanning options, which are overkill for what will be done in this book.

Nmap is installed with the following command:

sudo apt-get install nmap

Answer Yes to install Nmap and its dependent packages.

Using Nmap

After it is installed, run the following command to see all the hosts that are currently on the network:

nmap –T4 –F <your_local_ip_range>

The option -T4 sets the timing template to be used, and the -F option is for fast scanning. There are other options that can be used and found via the Nmap manpage.

Here, your_local_ip_range is within the range of addresses assigned by your router.

Here's a node scan of my local network. If you have a lot of devices on your local network, this command may take a long time to complete.

Now, I know that I have more nodes on my network, but they don't show up. This is because...