title: EHOSTUNREACH on UDP recvmsg
body: <p>Little bit confused on this issue :-).  I have some code running on Ubuntu 10.04, which is using the recvmsg call to receive Audio UDP packets.  This piece is part of a bigger SIP client which I've been testing with a remote system across the net.  </p>
  
  <p>Typically I am able to establish a call no problem and audio happily travels from the remote source to my program.  However after a random amount of time I'm running into a read error on the port.  When this happens I get the errno EHOSTUNREACH.  On this error I shutdown my port and kill the connection.</p>
  
  <p>The strange thing about this is that I was under the impression that this would happen in response to an ICMP message.  Perhaps due to a momentary network glitch.  However after reproducing this issue and doing a full packet capture, all I saw where ICMP pings and responses.  I didn't see any of the ICMP error messages that the kernel interprets as EHOSTUNREACH.</p>
  
  <p>My UDP port is pretty basic.  I can post the code if its really needed.  But this is just a basic SOCK_DGRAM. The socket is able to receive data for upwards of 8 hours sometimes before it hits this error condition.</p>
  
  <p>Any ideas how I can further tackle this issue.  I'm trying to understand why I'm receiving this errno with no ICMP message to correlate it with.</p>