[net-security] sometimes dumbest try hits hardest, our lovely 'Port Scan'

even the dumbest tries could hit opponent real hard... that is how the case is with Port Scanning today.

almost every Network Techie knows its importance and ways to secure them,
still everyone does leave a gap or even if no gap is left... its too hard to make network services hide their basic instincts and leave no trace...

 Normally, you shouldn't hope for any big revelations... but you can always crawl after the probable services active and their versions.

so a general procedure you can follow for some thrill is

Method:
perform it externally on available network resources and an internal multi-style scan
1. Simple Port Scanning
Doing a plain 'intensive mode' port scanning for all the ports from outside the network.
Do it for more specific ports on internal network, otherwise you could overflow your network routing tables or say DDoS your own lan. Know-More-About-it-Link
2. No-Ping Port Scanning ('n few more scan-modes)
Next, doing a scan in No-Ping mode made the Port-Scanner assume the host is already up and scan for the host's open ports. In certain better protected network scenarios, this is more successful than earlier style. Know-More-About-it-Link
3. Firewalking (just for fun... but you'll learn a lot)
In external scanning task, you could also use this old-school trick just to have some fun and try your luck to its limit. Know-More-About-it-Link


Tools/Technology Used: 
NMap, PortBunny, Telnet, Firewalk and NetCat present on BackTrack pen-test distribution.