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From: "Hard__warE" <hard__ware@hotmail.com>
To: netfilter@lists.samba.org
Subject: Flag SYN not necessarily state NEW?
Date: Sat, 15 Jun 2002 12:35:35 +1000	[thread overview]
Message-ID: <000501c21415$544d0e40$7b0010ac@dynamicaccess.lan> (raw)



>>On Wed, 8 May 2002, Ing. Christian Ogris wrote:
>> I connect from Box A via SSH to Box B, where the firewall runs, and i
>>get the state "NEW" on the first packet.
>> Then - the first connection is still established - i connect AGAIN from
>>Box A to Box B and do NOT get the state "NEW" anymore. (So obviously
>> it's already accepted by the ESTABLISHED,RELATED -j ACCEPT rule).
>> Is this behavior correct?

>No. But so far nobody has reported such an ill-behaviour. I assume
>something is wrong in your setup/logging.
>
>Regards,
>Jozsef



I have tested this as im running SSH ans as you can see hear in the print
out of my packets that
i dont even need a Established Related Rule for SSH from the Internet or
Internaly , this is handled
by IP_conntrack moddule and so on .. :-) .


(Notice My SSH Box has its own IP on the Firewall (yet i have still
restricted access to the box as only SSH)

Chain OUTPUT (policy DROP 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source
destination

51 38424 ACCEPT     all  --  *      eth0    172.16.0.22
172.16.0.0/16

/> netstat -C

Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 yes-dave.dynamicacc:ssh 172.16.0.123:2867
ESTABLISHED
Active UNIX domain sockets (w/o servers)

&
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 yes-dave.dynamicacc:ssh 172.16.0.123:2872
ESTABLISHED
tcp        0      0 yes-dave.dynamicacc:ssh 172.16.0.123:2871
ESTABLISHED
tcp        0      0 yes-dave.dynamicacc:ssh 172.16.0.123:2867
ESTABLISHED
Active UNIX domain sockets (w/o servers)
Proto RefCnt Flags       Type       State         I-Node Path



when i connect the first time (have not logged on yet) my SSH server says
the connecttion is already
ESTABLISHED and not NEW , and thats the same for evey connection after this
. The reason behind this is
SSH needs to establish a ESTABLISHED connection to the server before any
data is correctly Encrypted .. :D




             reply	other threads:[~2002-06-15  2:35 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2002-06-15  2:35 Hard__warE [this message]
2002-06-15 12:33 ` Flag SYN not necessarily state NEW? Matthew Hellman
2002-06-15 14:52   ` Chris
2002-06-15 12:35 ` default gateway problem Kumar
2002-06-15 12:48   ` Antony Stone
2002-06-15 21:57 ` Flag SYN not necessarily state NEW? Jozsef Kadlecsik
2002-06-16 18:04 ` Geog Hofstetter
2002-06-16 18:30   ` Antony Stone
2002-06-16 19:20     ` [x] - " Geog Hofstetter
     [not found] <20020507115906.8B112471A@lists.samba.org>
2002-05-08  6:45 ` Ing. Christian Ogris
2002-06-14 11:17   ` Jozsef Kadlecsik

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