title: What is Wireshark and WinPcap?
body: <p>I'm working with a WCF service I wrote a few years back, which uses TCP.  It's causing me problems saying, “…the target machine actively refused” my attempting to connect to it.  I've no idea why the target machine (our Windows 2003 Server) should now be actively refusing my connecting to it, when just last week it was all hunky-dory.  I've asked on the MSDN forums, and was told to run something called Wireshark.  I've never heard of it.  Is Wireshark sort of like Fiddler, only including other protocols besides HTTP?</p>
  
  <p>And another thing.  I've downloaded Wireshark and have started to install it.  Early on in the installation it informed me that it wants to update something called WinPcap.  I've never heard of that, either.  I've done another search on that and have found on Wikipedia and see that it is the Windows version of pcap, which stands for packet capture.  And according to Wireshark's website, whatever version of WinPcap currently on my system is, “… annoying bugs …” and version 4.1.2 of WinPcap fixes them.  OK, that's nice and all, but frankly satisfying Wireshark's needs alone isn't what I'm here to do.  I'd like to know what impact replacing WinPcap will have on my system.  What else relies upon WinPcap?</p>