Article by James Hawkins
As we all know, Nmap (Network Mapper) is a stealth port scanner widely used by network security experts (including forensics & Pen-testing Experts). In this article we’ll see the different types of Nmap Scans, its techniques, understanding the purpose and goals of each scan , its advantages or disadvantages over other scanning tools, which could be better at evading firewalls & IDS (To a certain extent) and much more. In this first part, I have made my best to explain the basic scanning techniques, Host discovery options, port scanning options, techniques used in detecting Operating system & services running on the system.
i also give Nmap as already installed on your system.