How to ping proxies ? ie in IP:PORT format

Well I decided to try make a proxy checker, like Charion or Elite proxy checker. These programs accept large lists of proxies in the IP:PORT format, ping them tell you the response time

see the screenshot of Elite Proxy Checker, im trying to make a simplified version of this program. http://i52.tinypic.com/a57slh.jpg

I investigated and made my checker using Ping.SendAsync(ip, timeout, ip) method. It was only afterwards that I discovered that you can only Ping IP's using this method, not the ports as well.

Ive spent a few hours trying to find the correct class/methods in order to be able to ping ports, reading different forum posts from experts they say its im开发者_如何学Pythonpossible to ping ports only IPS, can only use sockets to try open a connection with the port.

However, I have seen programs that people have coded in VB.NET that ping in the IP:PORT format, ie lets you choose timeout, tells timeout, etc.

My question is , what classes methods should I be using to do this ?

Im pretty sure its not sockets... theyve got to be pinging the individual ports as well somehow.

Any help would be appreciated.

Cheers,

(I code for a hobby, im not a pro, so sorry if I make glaring errors)

Have a look at tcpping, here is the Windows version:

http://www.elifulkerson.com/projects/tcping.php