Fastest way to determine and open/closed udp/tcp port

[emat]

Hi all,

I'm trying to make a script that checks weather a certain tcp or udp port is open, yes or no.

I'm wondering what's the fastest way to determine a tcp or udp is open or closed?

What should I be using?

 

[TrojanWarBlade]

This is an interesting problem.
An open port is easy cos you'll get an answer.
A closed port is a different issue completely.
Here you wait for a timeout so I guess it's down to how long you want to wait. If you timeout too quickly you'll miss open ports on busy or slow servers. If you wait a long time you'll be slow.
The choice is yours I guess!


Trojan.