Port Scanning Basics

Nerd Cafe | نرد کافه

What is a port scan?

Testing TCP/UDP ports to determine:

• Open

• Closed

• Filtered

Default scan

$ nmap scanme.nmap.org

Starting Nmap 7.94 ( https://nmap.org ) at 2026-02-10 20:31 Iran Standard Time
Nmap scan report for scanme.nmap.org (69.197.146.179)
Host is up (0.24s latency).
Other addresses for scanme.nmap.org (not scanned): 188.40.181.50 50.7.85.218 50.7.85.220 188.40.181.51 88.99.249.74 178.63.240.96 188.40.181.48 50.7.87.82 50.7.85.219 69.197.146.178 204.12.192.219 50.7.87.83 178.63.240.97 69.197.138.82 188.40.181.49 50.7.87.85 50.7.87.86 50.7.85.222 50.7.87.84 204.12.192.218 50.7.85.221 69.197.138.83
rDNS record for 69.197.146.179: gold.ottomanlike.com
Not shown: 995 closed tcp ports (reset)
PORT     STATE SERVICE
80/tcp   open  http
443/tcp  open  https
5810/tcp open  unknown
8888/tcp open  sun-answerbook
9100/tcp open  jetdirect

Nmap done: 1 IP address (1 host up) scanned in 17.50 seconds

Port states

State	Meaning
open	Service actively listening
closed	No service, but host reachable
filtered	Firewall blocking response

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Keywords

Nmap, Red Team, Blue Team, Reconnaissance, Port Scanning, Host Discovery, Service Enumeration, OS Fingerprinting, NSE Scripts, SYN Scan, IDS Detection, SIEM Correlation, Network Telemetry, Firewall Evasion, Timing Templates, Attack Surface, Defensive Monitoring, Incident Response, Purple Teaming, MITRE ATT&CK, nerd cafe , نرد کافه

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