Three stories of socket calls on tcp-lan's network (exchange, closedPort,
lostData): every frame with TCP flags and numbers, when each call started,
returned or failed, and each socket's states. Network building and the
packet log move from DhcpRun to ScenarioNetwork.
Measured: 3 RTT per attempt (8250 ms at 90 %), an orderly close after a
failed send, TIME_WAIT of 3 RTT, the passive side closing by itself on FIN,
one SYN only (Java's retry loop ends after the first timeout).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
