Hrm, strange.
The syncookie sysctl only has an effect on tcp options
once a listening sockets' syn queue is full. And even if you lose all
the tcp options -- without tcp_syncookies=1, the connection request
would have been discarded. So I do not really understand why they
shouldn't default to 1. I've sent patches for both points raised
(no warning about syn queue overflow if cookies are disabled,
syncookies sysctl defaults to 0), lets see what happens :-)
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