Nmap
Nmap (Network Mapper
) is a free and open source utility for network discovery and security auditing.
Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime.
Nmap uses raw IP packets in novel ways to determine what hosts are available on the network, what services (application name and version) those hosts are offering, what operating systems (and OS versions) they are running, what type of packet filters/firewalls are in use, and dozens of other characteristics.
Nmap runs on all major computer operating systems, and official binary packages are available for Linux, Windows, and Mac OS X.
Original author(s) : Gordon Lyon (Fyodor)
Initial release : September 1997
Repository : github.com/nmap/nmap
Written in : C, C++, Python, Lua
Operating system : Cross–platform
Type : Network security
License : Modified GPLv2
Website : nmap.org
Nmap is ...
Nmap supports dozens of advanced techniques for mapping out networks filled with IP filters, firewalls, routers, and other obstacles. This includes many port scanning mechanisms (both TCP & UDP), OS detection, version detection, ping sweeps, and more.
Nmap has been used to scan huge networks of literally hundreds of thousands of machines.
Most operating systems are supported, including Linux, Microsoft Windows, FreeBSD, OpenBSD, Solaris, IRIX, Mac OS X, HP–UX, NetBSD, Sun OS, Amiga, and more.
While Nmap offers a rich set of advanced features for power users, you can start out as simply as < q>nmap –v –A targethost. Both traditional command line and graphical (GUI) versions are available to suit your preference.
The primary goals of the Nmap Project is to help make the Internet a little more secure and to provide administrators/auditors/hackers with an advanced tool for exploring their networks. Nmap is available for free download.
Thousands of people download Nmap every day, and it is included with many operating systems (Redhat Linux, Debian Linux, Gentoo, FreeBSD, OpenBSD, etc). It is among the top ten (out of 30,000) programs at the Freshmeat.Net repository.
Here is a small Introduction to Zenmap
Zenmap is the official Nmap Security Scanner GUI. It is a multi–platform (Linux, Windows, Mac OS X, BSD, etc.) free and open source application which aims to make Nmap easy for beginners to use while providing advanced features for experienced Nmap users.
Zenmap is not meant to replace Nmap, but to make it more useful.
Zenmap can display Nmap's normal output, but you can also arrange its display to show all ports on a host or all hosts running a particular service. It summarizes details about a single host or a com scan in a convenient display. You can even use Zenmap to draw a topology map of discovered networks.
You can use Zenmap to graphically show the differences between two scans. This can help you to track new hosts or services appearing on their networks, or existing ones going down.
You can use Zenmap's command profiles to run the same scan more than once.
Zenmap is easy to use and is especially useful for people without much experience in Linux shell.