Strange RST ACK message after data message
I'm running a web services server on a debian machine, and our web services client is complaining about some random TCP resets he's receiving. I've installed tcpdump in the web server and I'm also seeing this RST ACK sent by my server immediately after a data message, for me this is very strange because the reset is not a reply to some message from the client (for example for a message out of the TCP window). Can you help me to clarify in what situation can this RST ACK occur? The log is attached, as you can see there is a client connection, a XML-RPC request (frame 598), my server sends TCP ACK (frame 599), then it sends HTTP 200 (OK) (frame 600) and immediately after (5 miliseconds) sends a RST ACK (frame 601). Is it possible that the application implementing the web service is causing the problem (for example not sending all the expected bytes to the socket)? In what situations this can occur?
Thanks in advance