title: TCP handshake not happening between windows client and linux server
body: <p>I'm really scratching my head around this one.</p>
  <p>I'm running a java server against a few test cases through a test tool and I'm getting a java socket timed out exception. The test tool runs on windows, while my server is deployed on a Raspbian. The test tool is black box so I do not know its implementation.</p>
  <p>From what I gathered, the test case creates a client sending an http address to my server, say <a href="http://192.168.1.100:8080" rel="nofollow noreferrer">http://192.168.1.100:8080</a>, in which my server is to make a connection and send data back to it. The port number is not static.</p>
  <p>I verified that the port is opened by the system each test. I then placed Wireshark on the test tool's machine and found that the Syn packet made it to the machine, but Syn/Ack was never sent out.
  I'm using java httpURLConnection, but I've also tried to make a java socket but both resulted in the same and throwing a socket timed out.</p>
  <p>This problem does not come up if I run the server locally with with the test tool. What make this stranger is that it also happens to another code base, which is supposed to pass the test.</p>
  <p>I don't know why it would not connect to the port.</p>
  <p>More information: I'm working on an Onvif device controller. Onvif essentially provides a common interface between video streaming device and client applications. The server needs to conform to Onvif specs and passes the Onvif device test tool.</p>
  <p>The problem above happens with test cases related to base event handlings, which follows <a href="http://docs.oasis-open.org/wsn/wsn-ws_base_notification-1.3-spec-os.pdf" rel="nofollow noreferrer">WS-BaseNotification</a> specs.The serer is given an endpoint so it can use to notify the client. However, given that that I'm getting a socket timed out, I don't think it is a schema parsing problem. The server throw an exception before any data was written to the output stream. The same problem happens with another code base which is supposed to be pass the test tool but the test tool also report that the notification was not delivered.</p>