Angry IP scanner is a very fast IP address and port scanner. It can scan IP addresses in any range as well as any their ports. It is cross-platform and lightweight. Not requiring any installations, it can be freely copied and used anywhere.
Reliable and free network scanner to analyse LAN. The program shows all network devices, gives you access to shared folders, provides remote control of computers (via RDP and Radmin), and can even remotely switch computers off. It is easy to use and runs as a portable edition.
Advanced Port Scanner is a fast and free software for port scanning. It will allow you to quickly find all open ports (TCP and UDP) and detect versions of programs running on them. The utility includes many features simplifying network management.
Dipiscan is a free IP scanner that allows you to remotely retrieve information about machines on your network using a clear and ergonomic interface (as well as a command-line mode) . It also includes wakeonlan/shutdown and other advanced features.
Umit: The Nmap Frontend: Umit was designed to accomodate and run more than one scan at time. Each scan is executed and shown inside a Scan Tab, which has a title and organize every information obtained in the scan result.
The IPPINGER is an application for checking a host or multiple hosts periodically. It can check IPs, websites and also ports (if are open). It can be configured to notify by email or Windows Notification when a host is down.