In our network, we repeatedly have problems, that network connection suddenly
drops but is available again right away. After that happened, I only see the
"Connected to.." popup in Windows taskbar - that's how I recognized the
connection loss. I don't know why this happens, and it's usually no problem
during work (but network guys couldn't yet give me an answer).

In such a case, a Hudson slave (running on a computer where this happens)
terminates (Hudson slave window shows state "Terminated"). After the network
connection being available again, the slave tries to reconnect to the master,
but it fails. Hudson slave window shows state "Handshaking" and then an
EOFException occurs. See following stack:

java.io.EOFException: unexpected stream termination
at hudson.remoting.Channel.<init>(Channel.java:312)
at hudson.remoting.Channel.<init>(Channel.java:251)
at hudson.remoting.Channel.<init>(Channel.java:239)
at hudson.remoting.Engine.run(Engine.java:159)

In order to reproduce the problem, simply deactivate your LAN connection in
Windows control panel (you will see Hudson slave window showing state
"Terminated") and then re-activate it (then you see state "Handshaking" and the
EOFException).

As this is easily reproducable for me, I suppose it is not a problem with our
network infrastructure, but a bug in Hudson slave implementation when
reconnecting to the master.