Port sniffer for my own machine:

Can someone please help me with this problem. I want to write a program that will detect an open port on my own machine. This is not malicious in any way. The reason why I need to write this is because I have manually opened multiple ports for multiple games on my machine now for some reason I can telnet to some of them leading me to believe that they are still open. I would like to write a program that will send data to those files to see if they are accepted or basically test to see if they are actually opened. I know this is pretty advanced and might be out of my scope for those of you who know me, but some tips or even links would be a help. I have already googled this issue but all that comes up is programs people have written and are charging outlandish prices for. I have basic knowledge of programing with sockets and average knowledge with networking but beginner when it comes to putting it all together. Any help will do.

Oh ya, I have already tryed to close them manually by deleting the program from the active directory in the firewall settings but some I still use, and when i bring up properties it only gives me the location of the program and the option to open more.

Windows? Try typing 'NETSTAT' in the console.

netstat /? for instructions.

You've posted this under C/C++... so not sure if you're looking to create your own.

A good industry tool would be nmap, it's free!.
It'll scan your own computer, or computers on your home network.
nmap is operating system agnostic... =)

Thanks Guys As Always. I've have been busy with a new job, but I will soon have my own computer to check the forums. Well actually three but the other two are IBM's and the internet is locked. =(
Itsacon,
But anyways, The netstat worked fine and I remember that one but forgot what it did, I guess what I really needed is to find out what programs are using what ports and with xp it doesn't realy have those type of options.
Madcowdzz,
Thanks for the tool man.
Expansion, =)
But let me expand on the question a little. If I am on an internal IP, being that I am behind a router will I have to forward all the ports for my games and stuff to the routed machine? Or is that even necessary. or can you just manually open a port and get the same effect, I know this is a programming page but I am still interested in this stuff because knowing about how this stuff works will better help me when its time to program something of this nature Im sure.

I have Kerio running on my own machine, which can give me a very comprehensive list of every program listening to, or sending on a port.

Also IMHO one of the best free firewalls around.

If you're behind a router, you'll need a port-forward to play most games, that's right.

Yes I have heard that about Kerio too, matter affact me and one of my bosses the other day were discussing this same subject and he said almost the same thing. But, when you say "you'll need a port-forward to play most games, that's right." is there another way then actually setting it up in your settings of linksys or whichever router you are using. If there is an easier way that would be kool, because I dont have admin rights to the router at the moment, my room mate does and he doesn't even know what a router is let alone what port forwarding is. So, its difficult to switch stuff, but if there is a program that I can use that does this for me and can keep a list of them that would be sweet. Thanks for all ya'lls help again.

Nope, most routers don't allow it without the root password.
There are different ways to do it. My old modem/router (before I moved here and got university broadband) was configured over telnet, and could be set by programs that handled the telnet connection themselves.
Those programs were simple command line tools, that could take config files, so you could set up configs for all your games.

But I don't think Linksys supports that.
I'd try gettting the password of your roommate. I believe the default setting for LS routers is username: <blank>, password: 'admin'. If he doesn't have a clue, it might still be on that.

I was going to state exactly that... additionally, if the password is still the default, CHANGE IT!
Or advise your flatmate to.

Ya, I got it all together now, I just put my router back on without him even knowing it, and being that the routers passwords are router specific and not service provider specific it all works out for every one. NOW the person that has a better change of messing things up has the admin rights, LOL dont laugh, hehehe. But Ill geterdid now. Ty fellas.

No prob, as usual :-)

I trust you've changed your password from the default anyhow? =)

I sure have