title: How to listen at the network layer?
body: <p>Programs like AdMuncher seem to intercept packets at the network layer before it ever reaches whatever protocol it is using. I want to do something similar, basically analyze each packet as it comes into the system and filter/rewrite, etc.. I know I can essentially write a proxy (or setup a proxy) to do similar, but I would like to intercept it before it even reaches that point.</p>
  
  <p>Not looking for any specific language, but if it is possible with C# that would be nice.</p>