КАК NMAP ЭТО ДЕЛАЕТ???!??!?! 0

longobard ~ # nmap -sS -O -P0 longobard.local

Starting nmap 3.70 ( http://www.insecure.org/nmap/ ) at 2004-09-20 17:46 MSD

Insufficient responses for TCP sequencing (3), OS detection may be less accurate

Interesting ports on longobard.local (10.1.7.90):

(The 1654 ports scanned but not shown below are in state: closed)

PORT STATE SERVICE

21/tcp open ftp

22/tcp open ssh

80/tcp open http

631/tcp open ipp

3128/tcp open squid-http

5432/tcp open postgres

Device type: general purpose

Running: Linux 2.4.X|2.5.X|2.6.X

OS details: Linux 2.4.0 — 2.5.20, Gentoo 1.2 linux (Kernel 2.4.19-gentoo-rc5), Linux 2.4.20, Linux 2.4.20 — 2.4.22 w/grsecurity.org patch, Linux 2.5.25 — 2.6.3 or Gentoo 1.2 Linux 2.4.19 rc1-rc7)

Uptime 2.930 days (since Fri Sep 17 19:28:00 2004)

Nmap run completed — 1 IP address (1 host up) scanned in 2.231 seconds

longobard ~ #

Вопрос: КАК НМАП УЗНАЛ МОЙ АПТАЙМ?!??!??!?!??!