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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Jerome,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Looking at your request again, it’s not clear what you’re trying to do. You say “at the beginning of the forward chain” but you use “-A” (append … as in, at the end). You use “-i tun0” which would be packets coming into linux on tun0 (from JNOS), as opposed to packets from linux going out tun0 to JNOS.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>If what you really want to do is:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>1) insert a rule at the beginning of the forward chain<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>2) filter packets outbound from linux to JNOS <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>2) drop if source address is 44.1.1.1<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>And assuming<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>a) you’ve got linux doing the gateway function<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>b) the interace between linux and JNOS is tun0<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Then:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>iptables –I FORWARD –o tun0 –s 44.1.1.1 –j DROP<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>If that’s not what you mean, then perhaps you could state what you mean more precisely.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'>Michael<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> nos-bbs [mailto:nos-bbs-bounces@tapr.org] <b>On Behalf Of </b>Michael Fox - N6MEF<br><b>Sent:</b> Friday, July 24, 2015 12:46 PM<br><b>To:</b> jerome schatten <romers@shaw.ca>; nos-bbs <nos-bbs@tapr.org><br><b>Subject:</b> Re: [nos-bbs] iptables and jnos question<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Jerome,<o:p></o:p></p></div><div><p class=MsoNormal>If you filter the input table, then the packet is still in the encapsulated state. You're looking and the tunnel addresses.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>You can filter on the forwarding table, on the tunnel between linux and jnos. At that point, the packet has been decapsulated and the original IP is the source address.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Michael<o:p></o:p></p></div><div><p class=MsoNormal>N6MEF<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div id="composer_signature"><div><p class=MsoNormal><span style='font-size:10.0pt;color:#575757'>Sent from my Verizon Wireless 4G LTE smartphone<o:p></o:p></span></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><span style='color:black'>-------- Original message --------<br>From: jerome schatten <<a href="mailto:romers@shaw.ca">romers@shaw.ca</a>> <br>Date: 07/24/2015 9:06 AM (GMT-08:00) <br>To: nos-bbs <<a href="mailto:nos-bbs@tapr.org">nos-bbs@tapr.org</a>> <br>Subject: [nos-bbs] iptables and jnos question <o:p></o:p></span></p><p class=MsoNormal>Hi...<br><br>I have been trying to construct a firewall rule to filter on the 44 <br>address of an ipip encapsulated packet rather than the 'carrier <br>address'. I've tried all sorts of variations of:<br><br>iptables -A FORWARD -i tun0 -s 44.x.x.x -j DROP<br><br>at the beginning of the forward chain with no success. I'm beginning to <br>get the feeling that it is may not possible to filter on the <br>encapsulated ip.<br><br>Thanks for any suggestions,<br>jerome - ve7ass<br><br><br>_______________________________________________<br>nos-bbs mailing list<br><a href="mailto:nos-bbs@tapr.org">nos-bbs@tapr.org</a><br><a href="http://www.tapr.org/mailman/listinfo/nos-bbs">http://www.tapr.org/mailman/listinfo/nos-bbs</a><o:p></o:p></p></div></div></body></html>