Gordon Lyon - (Free)
Nmap is a powerful and indispensable tool for all network administrators developed to explore and perform an audit or a computer network hardware inventory.
Nmap ("Network Mapper") is a software application that allows to detect open ports as well as information on a remote computer. Network administrators can use to identify the network status, manage schedules update services and monitor the availability of each item.
Using uses TCP, ICMP, IP or UDP it identifies services hosted on a computer. Thus, information such as the operating system or available ports can be accessed. Specific reports also allow to perform a specific audit of the safety and security of the system.
The functional graphical user interface provides access to a wealth of information at the first glance.