I have a JNLP slave running on a remote Windows server. Due to the fact that communication goes over the internet, at times the connectivity between the master and the slave will be broken.

When connectivity is reestablished though the slave will not try to reconnect with the master. A reset of the Windows service hosting the slave re-established connection and the slave becomes available in the master.

An error message is recorded here. This error as far as I can see occurs at the time network connectivity is lost, and the "INFO: Terminated" shows that slave indeed have "died".
NOTE: even though the Java code has terminated, the Windows service is still running.

feb 17, 2013 3:33:18 AM hudson.remoting.jnlp.Main$CuiListener <init>
INFO: Hudson agent is running in headless mode.
feb 17, 2013 3:33:18 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Locating server among https://externalyavailabledomain/build/, http://internalmasterserver:8080/build/
feb 17, 2013 3:33:19 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Connecting to externalyavailabledomain:50456
feb 17, 2013 3:33:19 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Handshaking
feb 17, 2013 3:33:19 AM hudson.remoting.jnlp.Main$CuiListener status
INFO: Connected
feb 17, 2013 1:59:20 PM hudson.remoting.SynchronousCommandTransport$ReaderThread run
SEVERE: I/O error in channel channel
java.net.SocketException: Connection reset
at java.net.SocketInputStream.read(Unknown Source)
at java.net.SocketInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
at java.io.ObjectInputStream$PeekInputStream.peek(Unknown Source)
at java.io.ObjectInputStream$BlockDataInputStream.peek(Unknown Source)
at java.io.ObjectInputStream$BlockDataInputStream.peekByte(Unknown Source)
at java.io.ObjectInputStream.readObject0(Unknown Source)
at java.io.ObjectInputStream.readObject(Unknown Source)
at hudson.remoting.Command.readFrom(Command.java:90)
at hudson.remoting.ClassicCommandTransport.read(ClassicCommandTransport.java:59)
at hudson.remoting.SynchronousCommandTransport$ReaderThread.run(SynchronousCommandTransport.java:48)

feb 17, 2013 1:59:20 PM hudson.remoting.jnlp.Main$CuiListener status
INFO: Terminated