> Isn't that exactly what the automatic closing is supposed to prevent? Couldn't deliberate or accidental connection interruptions eventually cause a DOS? Yes,

> Isn't that exactly what the automatic closing is supposed to prevent? Couldn't deliberate or accidental connection interruptions eventually cause a DOS? Yes, exactly. My point was that until the application closes the file descriptor, it's up to the application to deal with that issue. (Many public-facing web servers close idle sockets for this reason.) Only once the application has closed the socket does it become the TCP stack's responsibility, and that's why the 60-second timer exists. But that timer exists only for sockets whose file descriptors are closed.