listen for data on TCP port C#

Question

Hi all

I would like to write a program that monitors for TCP ports, similar to TcpView, but the thing is, it must fire off events if certain ports are used. The scenario:

License server, and client-program. The license server may use port 1234 to listen and establish multiple connections. The client connects from his pc to the server via port 1234.

When a packet is sent/received on that port, an event must be triggered on the client PC.

Any ideas where to start? (Have googled, and stumbled across old sites with useless info)

Regards,

Answer 1

It sounds like you will want to use the HTTPListener class on the server side.

http://msdn.microsoft.com/en-us/library/system.net.httplistener.aspx

The HTTPListener will bind to a TCP port and listen for any incoming connections. Once a connection is detected it will fire an event which you can handle and do any required processing.

Answer 2

I think you're looking to set up a simple TCP server, like this:

http://www.switchonthecode.com/tutorials/csharp-tutorial-simple-threaded-tcp-server

Answer 3

This project makes it : sharp pcap or here sharp pcap

Answer 4

In order to sniff packets, I recommend a great WinPcap wrapper to use in C# or VB.NET (.NET wrapper) called Pcap.Net: http://pcapdotnet.codeplex.com