1. Ping sweep
-sn is a host-discovery ping sweep: it finds which hosts in the authorized range are alive without scanning ports.
nmap -sn 10.0.0.0/24Typorithm · medium
nmap Scanning
nmap-reconsecuritynmapscanningrecon
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Step 1 of 8 · intro card
Learn nmap Scanning
Network Security
With written authorization, nmap maps a network: -sn pings hosts to find what is live, -sS runs a stealth SYN port scan, -sV detects service versions, -O fingerprints the OS, and --script vuln probes known weaknesses. This is the reconnaissance phase of an approved assessment — and exactly what defenders watch for.
Reconnaissance is the first phase of any authorized security assessment. With explicit, written permission to test, nmap discovers which hosts are alive, which ports are open, and which services answer.
-sn is a ping sweep that only finds live hosts. -sS is a stealth SYN scan that maps open ports without completing the TCP handshake. -sV detects each service's version and -O fingerprints the operating system, building a picture of the attack surface.
--script vuln runs Nmap Scripting Engine checks for known vulnerabilities. Run only against systems in your authorized scope — and remember defenders see these scans, so unexpected probes are a red flag in their monitoring.
01
-sn = ping sweep for live-host discovery.
02
-sS stealth SYN scan; -sV service versions; -O OS.
03
Scan only systems you are explicitly authorized to test.
nmap -sn 10.0.0.0/24
nmap -sS -p 1-1000 target
nmap -sV -O target
nmap --script vuln targetRead the implementation
Connect each part of the code to the concept before you type.
2. SYN scan
-sS is a stealth SYN scan; -p 1-1000 limits it to the first 1000 ports to map what is open.
nmap -sS -p 1-1000 target3. Service & OS detection
-sV detects the version of each service and -O fingerprints the operating system.
nmap -sV -O target4. Vuln scripts
--script vuln runs NSE scripts that probe known vulnerabilities — only against systems you are authorized to test.
nmap --script vuln targetA complete learning loop
01
Understand
Read the concept map and follow the code breakdown.
02
Reconstruct
Type the implementation, repair mistakes and work through every recall exercise.
03
Verify
Use the final check without hints; revisit weak concepts in short practice sessions.