Angry IP Scanner is a simple, lightweight and open-source network scanner that scans for IP addresses and ports, detects them, lists them, and provides handy additional information about them.
This tool is very small, simple, neat and lightweight. It doesn’t even require an installation. You can just download it and use it right away. Though it mostly depends on the size of the network, I noticed that the network scanning speed is pretty decent thanks to its multithreaded approach. It also lets you select the IP range and scan IP addresses only within that range. This can significantly improve the scanning speed and shorten the scanning time. Its modus operandi is pretty simple: it pings each IP address to check if it's alive, and if it is, the app attempts to resolve its hostname and retrieve additional related data such as the open ports. Plug-ins that allow retrieving even more data are also supported.
I also like about this tool the fact that it lets you filter the displayed results. You can choose the app to show only alive hosts. Furthermore, it can export the scan results to various file formats, such as CSV, TXT or XML. Many other additional features and options are still available, including a NetBIOS information retrieving function or a web server detection tool.
To sum it all up, Angry IP Scanner is a really nice and handy network scanner and the fact that it’s open-source makes it even more desirable.