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Re: DoS attack against TCP services

On 2015-01-19 10:24, Michael van Elst wrote: writes:

Unfortunately, all TCP connections are now in the TIME_WAIT state.

bash-4.3 # netstat -a -n | grep TIME_WAIT | wc -l

Is there a way to remove it without rebooting the server?


It works. But why doesn't drop the kernel it automatically?

TCP connections in TIME_WAIT will expire after some time, usually between
10 and 60 seconds after a connection is closed. The timeout depends on
the distance of the remote machine.

Timeout should not depend on distance, and should actually be (at least) 2*MSS, which would be something in the several minutes range. But apart from that - yes - the kernel should expire and remove sockets in TIME_WAIT after a while.

But I might be wrong, and the standards have changed. I'm mostly going on some rather old RFCs here...


Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email:             ||  Reading murder books
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