nmap port scanning commands 3 Mar 2026 Tuesday

Subject: nmap port scanning commands 3 Mar 2026 Tuesday

Good day from Singapore,

[01] nmap command to scan all 65535 TCP ports

nmap -p- -sS -sV -O -T4 -vv public_ip

What Each Option Does

-p- → Scan all 65,535 TCP ports

-sS → TCP SYN scan (standard for firewall auditing)

-sV → Service/version detection

-O → OS detection (helps verify what’s exposed externally)

-T4 → Faster timing, fine for Internet audit

[02] nmap command to scan all 65535 UDP ports

nmap -p- -sU -T4 -vv target_ip

What Each Option Does

-p- → Scan all 65,535 UDP ports

-sU → UDP scan

-sV → Service/version detection on open UDP ports

-O → OS detection

-T4 → Faster timing

[03] nmap command to scan list and range of TCP ports

nmap -sS -sV -p 22,80,443,1000-2000 -vv target_ip

[04] nmap command to scan list and range of UDP ports

nmap -sU -sV -p 53,123,500,1000-2000 -vv target_ip

Please remember to use Verbose Mode -vv.

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nmap scan - Aggressive Mode

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[05] nmap command to scan all 65535 TCP ports

nmap -p- -sS -A -T4 -vv target_ip

What This Does

-p- → Scan ports 1–65535

-sS → TCP SYN scan

-A → Aggressive mode (service + OS + scripts + traceroute)

-T4 → Faster timing

[06] nmap command to scan all 65535 UDP ports

nmap -p- -sU -A -T4 -vv target_ip

What -A Does in a UDP Scan

-A enables:

-sV → Service detection ✅ (useful for UDP)

-O → OS detection ⚠️ (often unreliable with UDP-only scans)

-sC → Default scripts

--traceroute

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Explanation for Aggressive Mode

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The -A (Aggressive) option in Nmap automatically enables:

-sV → Service/version detection

-O → OS detection

-sC → Default NSE scripts

--traceroute

So you do not need to specify -sV and -O separately if you use -A.

Regards,

Mr. Turritopsis Dohrnii Teo En Ming

Extremely Democratic People's Republic of Singapore

3 Mar 2026 Tuesday 11.18 pm Singapore Time

REFERENCES

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[1] https://lore.kernel.org/netdev/s8BZ4ns00wPBZEbsgBWUK5eBpQbqy5HJzBIbW7-IwO-JFYnTRPfitESS-6M7MUXEFiZitAVL0RR0i6JmxmNl-Yj72CLpSib83bhwgQzk3wY=@protonmail.com/

[2] mail-archive.com - NIL

[3] https://marc.info/?l=linux-netdev&m=177255442023159&w=2

[4] https://lists.freebsd.org/archives/freebsd-chat/2026-March/000071.html

[5] mail-archive.com - NIL

[6] https://marc.info/?l=freebsd-chat&m=177260418620886&w=2