I discovered lanmap during my stay in a hotel during the Merdeka holidays. This little handy tool can generate local area network map in PNG,SVG and GIF format by listening to network traffic from network interfaces.
lanmap does this by putting network interface in promiscuous mode and representing the data its sees into a 2-d human-readable network graph. It has the advantage of identifying the network traffic being passed around the network along with the name and the operating system of the host which are represented on the graphical representation as well.
My House Local Area Network
Local Area Network from a Hotel that I stayed in
You can download lanmap from its official website. Lanmap is licensed under the GNU General Public License version 2.0.