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From: Nemeth Denes <nemeth.denes@iit.bme.hu>
To: netfilter@vger.kernel.org
Subject: sequence numbers in conntrack
Date: Sat, 09 Jan 2010 22:12:38 +0100	[thread overview]
Message-ID: <4B48F146.4040303@iit.bme.hu> (raw)

Hello,

Could someone help me to explain what does the conntack module do
in TCP connection negotiation in the following three cases: (host N is
behind the NAT and host P is on the other side of the NAT)

A:
P sends a SYN to H and H replies with an SYN-ACK with an invalid
sequence number (If this passes normally through is it possible to
filter it out?)

B:
P sends a SYN to H and H replies with non SYN-ACK (3-way-handshake)
or SYN (TCP simultaneous open) package

C: If the "--random" option is given to the postrouting chain, what happens
if the clients use up all the ports?

Many thanks,
Denes Nemeth



             reply	other threads:[~2010-01-09 21:12 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-09 21:12 Nemeth Denes [this message]
2010-01-10  4:10 ` sequence numbers in conntrack vishesh
2010-01-10 10:06   ` Nemeth Denes
2010-01-10 11:03     ` Nemeth Denes

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