Introduction to Nmap and Network Scanning
What is Nmap?
Nmap, short for Network Mapper, is a powerful open-source tool used for network discovery and security auditing. It is widely used by cybersecurity professionals, network administrators, and penetration testers to gather information about network hosts, services, and vulnerabilities.
Network Scanning Basics
Network scanning is the process of identifying active hosts, open ports, and running services on a network. Nmap provides a variety of scanning techniques, including:
- TCP Connect Scan
- SYN Scan
- UDP Scan
- Idle/Zombie Scan
- and more
These scanning techniques can be used to gather information about the target network, such as the operating system, open ports, and running services.
Nmap Command-line Options
Nmap offers a wide range of command-line options that allow users to customize their scans and gather more detailed information about the target network. Some common Nmap options include:
-sV
: Probe open ports to determine service/version info
-sC
: Use default nmap scripts for further enumeration
-p-
: Scan all ports instead of just the most common 1000 ports
-oA
: Output all major output formats at once
Nmap Scripting Engine (NSE)
The Nmap Scripting Engine (NSE) is a powerful feature that allows users to write their own scripts to automate various network tasks. These scripts can be used to perform vulnerability scanning, service enumeration, and even exploit execution.
graph TD
A[Nmap] --> B[Network Scanning]
B --> C[TCP Connect Scan]
B --> D[SYN Scan]
B --> E[UDP Scan]
B --> F[Idle/Zombie Scan]
A --> G[Command-line Options]
A --> H[Nmap Scripting Engine (NSE)]