title: Stepping through a TCP/IP stack
body: <p>I was working as a QA engineer for a proprietary embedded operating system.  They built their own <a href="http://en.wikipedia.org/wiki/Aeronautical_Telecommunications_Network" rel="nofollow noreferrer">ATN stack</a> and stepping though it with a debugger was the most eye opening experience I have had with networking. Watching each layer of the stack build their part of the packet was amazing.  Then finally being able to see the built packet on the wire had more meaning.</p>
  
  <p>As an educator I would like share this experience with others.  Does anyone know of a straight forward method stepping though a TCP/IP stack?  Ideally I would like something easier than debugging a *BSD or Linux kernel, although if this is the only option then some tips and tricks for this process would be nice.  A reference stack written in C/C++ that could be run in user mode with Visual Studio or Eclipse would be ideal.</p>