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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>A little more information:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>When I added a rule in the INPUT chain I
get an immediate connection refused, yet when I remove it I get a lot of SYN
packets going to the server. I’m using tshark to view what is
happening.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>My setup for testing is as follows:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>My office one terminal session on my
firewall with tshark running:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Tshark –I eth0 port imap<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>My office one terminal session on my SuSE Linux
Desktop:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Telenet mail.destination.com.au 143<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Destination server:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Tshark –I eth0 port 143<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>I’ve opened the port 143 on both the
linux gateway server (iptables) and the Cisco router on the destination
site.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>J<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<hr size=2 width="100%" align=center tabindex=-1>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
plug-bounces@plug.org.au [mailto:plug-bounces@plug.org.au] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Jon Miller<br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, 9 December 2008
10:02 AM<br>
<b><span style='font-weight:bold'>To:</span></b> plug@plug.org.au<br>
<b><span style='font-weight:bold'>Subject:</span></b> [plug] firewall issue</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>I’m trying to open a port for imap and having a
bitch of a time at it.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>I have imap running from the following results:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'># nmap -n -O -p 143 -sS 192.168.1.100<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>Starting Nmap 4.11 ( http://www.insecure.org/nmap/ )
at 2008-12-09 09:21 WST<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>Warning: OS detection will be MUCH less
reliable because we did not find at least 1 open and 1 closed TCP port<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>Interesting ports on 192.168.1.100:<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>PORT STATE SERVICE<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>143/tcp open imap<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>MAC Address: 00:14:5E:2B:67:2A (IBM)<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>Device type: general purpose<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>Running: Novell NetWare 6.X<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>OS details: Novell NetWare 6 SP1<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>Nmap finished: 1 IP address (1 host up) scanned in
1.118 seconds<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'>The issue is in the iptables firewall.
I’m having the following rules:<o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:0cm;margin-right:.9pt;margin-bottom:
0cm;margin-left:13.85pt;margin-bottom:.0001pt;text-autospace:none'><font
size=2 color=black face="MS Shell Dlg"><span style='font-size:10.0pt;
font-family:"MS Shell Dlg";color:black'>$IPT -A FORWARD -i $INT_IFACE -d
192.168.1.100 -p tcp --dport 143 -j ACCEPT<o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:0cm;margin-right:.9pt;margin-bottom:
0cm;margin-left:13.85pt;margin-bottom:.0001pt;text-autospace:none'><font
size=2 color=black face="MS Shell Dlg"><span style='font-size:10.0pt;
font-family:"MS Shell Dlg";color:black'>$IPT -A FORWARD -i $INT_IFACE -s
192.168.1.100 -p tcp --dport 143 -j ACCEPT</span></font><font size=2
color=black face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:black'><o:p></o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:0cm;margin-right:.9pt;margin-bottom:
0cm;margin-left:13.85pt;margin-bottom:.0001pt;text-autospace:none'><font
size=2 color=black face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:0cm;margin-right:.9pt;margin-bottom:
0cm;margin-left:13.85pt;margin-bottom:.0001pt;text-autospace:none'><font
size=2 color=black face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:black'><o:p> </o:p></span></font></p>
<p class=MsoNormal style='mso-margin-top-alt:0cm;margin-right:.9pt;margin-bottom:
0cm;margin-left:13.85pt;margin-bottom:.0001pt;text-autospace:none'><font
size=2 color=black face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:black'> I have these 2 rules in, do I need to add more rules in the
INPUT and OUTPUT chains?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-AU style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
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