Nmap - is a software, which is a reduction in the title refers to the type of programs Network Mapper. As well as possible, the name can be translated as "Web Mapping". He is one of the most unique and interesting tools for testing network and its security. Most interesting is that the utility is a cross-platform, distributed free of charge and intended for use in any type of operating sictem, including Linux, Windows, FreeBSD, Open BSD, Solaris and Mac OS X.
Key Features Of Nmap
With regard to the main features, then get started is to say that the program has a fairly powerful tools to scan the network using different types of local connections. This includes UDP, TCP / IP, SYN, NULL, FTP proxy, Reverse-indent, ICMP, FIN, ACK. The choice of the scanning process in the environment of any operating system will depend on the choice of the keys specified on the command line. For some open ports and services, which are responsible for their operation, in some cases, enter the keys is not necessarily because the application has a list of the most commonly used, the default. When scanning program is able to recognize the four state ports, namely, open port, closed, filtered and not filtered. It is worth stopping in more detail. Open port means that the remote terminal is in a state of readiness to adopt and send packets during the scanning process. Closed port is such a very conditional, that is, at the moment it is not associated with any other running applications and can be opened at any time. The presence of the filter on the port only indicates that there are some third-party application that can block access to it. In most cases, it is simply a firewall operating system itself. Unfiltered port usually unresponsive program, but the application is not able to determine whether the port is open or closed.
If at the time of the scanning process by pressing a key or a combination thereof (for each OSes, it is set in its own way), you can see the progress of the scan and the percentage of executed and the remaining process. Among other things, the program allows you to define your own means, even if not the exact version of the kernel, at least, at least approximate date of the assembly. And the most interesting thing is that the scan is not limited to only one port. For a complete check available scan multiple ports. Performance of the program is based on the fact that this type of test is no more than a ping-test. If you have a full list of IP-addresses of terminals connected to the LAN, then the check will take even less time. The only thing you should pay attention to, so just the fact that some hosts do not respond to a ping-request due to the included firewall.
In conclusion, it should be said that this program is likely, it is designed more for system administrators, rather than the average user. Yes, this is understandable. After all, in the home local networks are not common. But for small and medium offices such administration tool fit, could not be more helpful. Finally I want to see that the developers warn that a port scan on the remote terminals in some cases may even be illegal.