Tcp listen limit.

[Fabio Yasusi Yamamoto]

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Hi folks.

Please, someone confirm if i'm right. if i'm wrong, please forgive-me.

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I've developed a little tool to stress test tcp connections.( Sending
syn and answer ack-syn ). that simuates a real tcp connection. (
http://www.hostname.org/fake_connect  )

And i notice that severals programs have a little tcp ( listen
backlog? ) limit.

One of these program was OpenSSH.  With this i can cause a temporary
DoS on  SSHd preventing any user to log-on. ( sometimes the real
connection is closed , somethimes it does't response  at all ( there
is no SYN-ACK ).

My target plataform was LINUX and FreeBSD.

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Here is my question:
~    It is possible in the configuration, to increase the connection
limit / listen backlog?
~    Why it is not by default?
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Before:
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bash-2.05b# telnet 10.30.0.1 22
Trying 10.30.0.1...
Connected to 10.30.0.1.
Escape character is '^]'.
SSH-1.99-OpenSSH_3.7.1p2

After
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bash-2.05b# telnet 10.30.0.1 22
Trying 10.30.0.1...
Connected to 10.30.0.1.
Escape character is '^]'.
Connection closed by foreign host.


On a massive stress:
bash-2.05b# telnet 10.30.0.1 22
Trying 10.30.0.1...
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