title: UDP and my computer?
body: <p>I recently turned on Windows Firewall logging on my computer and started tracking incoming and outgoing connections. Something curious about the logfiles is that I have noticed numerous UDP packets (in fact, it constitutes basically all of my incoming traffic) that don't have my host as destination or source showing up in the logs.</p>
  
  <p>I thought this might be a implementation detail for UDP (the packets are hopping over my computer in the subnet) but Wikipedia'ing UDP didn't enlighten me any more, and I don't see why my computer should be forwarding these packets in the first place.</p>
  
  <p>Any ideas?</p>
  
  <p><strong>Edit 1:</strong> Here is what a log file line with the mysterious UDP packet looks like:</p>
  
  <pre><code>2008-10-11 16:04:31 ALLOW UDP 18.243.7.218 239.255.255.250 49152 3702 0 - - - - - - - RECEIVE
  </code></pre>
  
  <p>Is 239.255.255.250 a broadcast address? Now that you mention it, the UDP packets I'm seeing have very specific destinations, basically 224.0.0.252, 239.255.255.250, 18.243.255.255. I also get phantom ICMP pings addressed to 224.0.0.1.</p>