27/01/2026
Nmap Network Scanning β Beginner Friendly Guide π₯
In Cyber Security & Ethical Hacking, the first and most important step is Network Scanning.
Before attacking or defending any system, we must know:
β Which devices are live
β Which IP addresses are active
β Which ports are open
For this, professionals use Nmap (Network Mapper) π
πΉ What is Network Scanning?
Network scanning helps to discover:
Live systems in a network
Private IP addresses (192.168.x.x)
Open ports and running services
β Private IP scanning only works when you are connected through:
Same network
VPN connection
πΉ Ping Scan (Find Live Hosts)
nmap -sn 192.168.1.0/24
β /24 = 256 IPs
β Shows which systems are online
nmap -v -sn 192.168.1.0/24
β -v = Verbose mode (step-by-step details)
πΉ TCP Scan
nmap -v -sT 192.168.1.1
β Full TCP connection
β Easy to detect
β Useful when SYN scan is blocked
πΉ SYN Scan (Stealth Scan)
nmap -v -sS 192.168.1.1
β Fast & stealthy
β Most popular scan
β Used by ethical hackers
πΉ Aggressive Scan
nmap -A 192.168.1.1
Finds:
β OS details
β Service versions
β Vulnerabilities
β Use only with permission.
πΉ Script Scan (NSE)
nmap -C 192.168.1.1
β Uses Nmap Scripting Engine
β Finds common security issues
πΉ Important Cyber Fact
π‘ One IP address has 65,535 ports
Open ports = possible security risks.
