I am playing with NMAP in my small private network performing port scanning.

So far I went through scanning the following OSs (Unaltered new installations - Meaning no extra software installed!):

  • Ubuntu 14.04
  • Windows 2012
  • Windows 2008 R2
  • Windows 7

Expect for W7, all other OSs returned ports opened. Is W7 this safe in its original version or am I missing any parameter in my NMAP command?

root@ubuntu-14:/# nmap -sS -vv

Starting Nmap 6.40 ( http://nmap.org ) at 2015-11-22 09:26 CET
Initiating ARP Ping Scan at 09:26
Scanning [1 port]
Completed ARP Ping Scan at 09:26, 0.20s elapsed (1 total hosts)
Initiating Parallel DNS resolution of 1 host. at 09:26
Completed Parallel DNS resolution of 1 host. at 09:26, 0.03s elapsed
Initiating SYN Stealth Scan at 09:26
Scanning [1000 ports]
Completed SYN Stealth Scan at 09:27, 27.95s elapsed (1000 total ports)
Nmap scan report for
Host is up (0.00045s latency).
All 1000 scanned ports on are filtered
MAC Address: 08:00:27:82:37:2A (Cadmus Computer Systems)

Read data files from: /usr/bin/../share/nmap
Nmap done: 1 IP address (1 host up) scanned in 28.24 seconds
           Raw packets sent: 2001 (88.028KB) | Rcvd: 1 (28B)

2 Answers 2


The phrase "safe against NMAP" does not make any sense. An NMAP scan is not an attack.

NMAP detects and reports open ports. It does not tell you whether these open ports serve a legitimate purpose and/or pose a security risk. Nor are open ports the only possible source of security risks. An NMAP scan is only one of many elements in a machine's security assessment. You can neither conclude that Windows 7 is safe just because NMAP reports no open ports nor that other OSes are less safe because NMAP does report open ports. This holds independently of the NMAP options you are using.


The safety measures is dependent on firewall configurations (inbound outbound) and the rules that are set in new installations of the OS's. Comparing operating system based on it's new installations is baseless.

Unless there are any services which require a particular TCP/IP port to be open, I see there is no point in comparison as other operating systems might ship with additional services. A open port doesn't always make a system vulnerable. It's how you configure your installation that makes the system vulnerable.

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