NMAP practice

Below is nmap sample in localhost. Localhost's nmap result and IP public's nmap result have different result. IP public's result have nothing port opened. Because I have blocked all my ports.

Localhost's nmap

~$ nmap localhost

Starting Nmap 4.76 ( http://nmap.org ) at 2009-03-24 09:15 WIT
Interesting ports on localhost (127.0.0.1):
Not shown: 997 closed ports
PORT STATE SERVICE
631/tcp open ipp
2126/tcp filtered unknown
8800/tcp filtered unknown

Nmap done: 1 IP address (1 host up) scanned in 608.55 seconds

IP public's nmap

tu:~ Akmal$ nmap ***.***.***.***

Starting Nmap 4.76 ( http://nmap.org ) at 2009-03-24 09:34 WIT
All 1000 scanned ports on tu-***.***.***.** (***.***.***.***) are closed

Nmap done: 1 IP address (1 host up) scanned in 8.02 seconds

Lecture-Assignment