Java: Network dropped connection on reset [duplicate]

Question

I've written a multi-threaded UDP Proxy in Java using DatagramChannels.

It works fine until the following exception appears:

java.net.SocketException: Network dropped connection on reset: no further information 
at sun.nio.ch.DatagramChannelImpl.receive0(Native Method) 
at sun.nio.ch.DatagramChannelImpl.receiveIntoNativeBuffer(Unknown Source) 
at sun.nio.ch.DatagramChannelImpl.receive(Unknown Source) 
at sun.nio.ch.DatagramChannelImpl.receive(Unknown Source) 
at com.fabio.rotumaster.proxy.ProxyMain.handlePacket(ProxyMain.java:189) 
at com.fabio.rotumaster.proxy.ProxyMain.run(ProxyMain.java:169) 
at java.lang.Thread.run(Unknown Source) 

In ProxyMain.java on line 189 there is only the receive method being called:

SocketAddress sender = this.clientChannel.receive(buffer);

The error appears randomly from time to time. Sometimes only once and sometimes 5 of them in a row.

Does anyone have an idea?

Answer 1

This is Winsock error 10052: WSAENETRESET:

Network dropped connection on reset.

The connection has been broken due to keep-alive activity detecting a failure while the operation was in progress. It can also be returned by setsockopt if an attempt is made to set SO_KEEPALIVE on a connection that has already failed.

How you can possibly get that on a UDP socket appears to be a mystery, but MSDN also says under recvfrom():

For a datagram socket, this error indicates that the time to live has expired.

And @David Schwartz says:

This is one of many errors that UDP implementations tend to uselessly report to applications. You pretty much have to ignore them all.