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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>O.K. Understood. But it’s better to just eliminate the problem than to have to build more complexity in order to avoid a problem that shouldn’t exist in the first place. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>And you also have to understand that there are lots of folks out there who don’t have the expertise to add more complexity. So we shouldn’t push more complexity as a “solution”, especially when it’s really just masking the problem. We should be doing everything we can to make implementations as simple as possible.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>M<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='margin-left:.5in'><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> nos-bbs-bounces@tapr.org [mailto:nos-bbs-bounces@tapr.org] <b>On Behalf Of </b>Bob Tenty<br><b>Sent:</b> Sunday, November 17, 2013 4:31 PM<br><b>To:</b> TAPR xNOS Mailing List<br><b>Subject:</b> Re: [nos-bbs] UDP Port Unreachable - problem found<o:p></o:p></span></p></div></div><p class=MsoNormal style='margin-left:.5in'><o:p> </o:p></p><div><p class=MsoNormal style='margin-left:.5in'>It doesn't matter or it is 44 addresses but encapsulation or better a VPN is a way out of the problems you have.<br>I have dealt with firewalls you have and much worse and always could find solution for an AXIP<br>or AXUDP.<br>Then there is OpenVPN what especially can deal with changing source ports if you use it in the client - server <br>configuration.<br><br>B<br><br>On 13-11-17 11:05 AM, Michael E. Fox - N6MEF wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal style='margin-left:.5in'><span style='color:#1F497D'>As I already mentioned: the other end is not running AMPRnet so this is straight NAT to the Internet, no encap.</span><o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'><span style='color:#1F497D'>M</span><o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'><span style='color:#1F497D'> </span><o:p></o:p></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='margin-left:1.0in'><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> <a href="mailto:nos-bbs-bounces@tapr.org">nos-bbs-bounces@tapr.org</a> [<a href="mailto:nos-bbs-bounces@tapr.org">mailto:nos-bbs-bounces@tapr.org</a>] <b>On Behalf Of </b>Bob Tenty<br><b>Sent:</b> Saturday, November 16, 2013 10:33 PM<br><b>To:</b> <a href="mailto:nos-bbs@tapr.org">nos-bbs@tapr.org</a><br><b>Subject:</b> Re: [nos-bbs] UDP Port Unreachable - problem found</span><o:p></o:p></p></div></div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p><div><p class=MsoNormal style='margin-left:1.0in'>Yes but I mean it in the context that you encapsulate the relevant 44 addresses at both sides.<br>(in the local lan addresses).<br><br><br>Bob VE3TOK<br><br>On 13-11-17 12:08 AM, Michael E Fox - N6MEF wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal style='margin-left:1.0in'>We are. But the addresses don't matter since both ends are behind a firewall. The addresses could be anything and the problem would be the same.<o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'>Michael<o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'>N6MEF<o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><div><p class=MsoNormal style='margin-left:1.0in'><span style='font-size:7.0pt;color:#575757'>Sent from my Verizon Wireless 4G LTE smartphone</span><o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:0in;margin-right:0in;margin-bottom:12.0pt;margin-left:1.0in'><br><br>-------- Original message --------<br>From: Bob Tenty <br>Date:11/16/2013 8:44 PM (GMT-08:00) <br>To: <a href="mailto:nos-bbs@tapr.org">nos-bbs@tapr.org</a> <br>Subject: Re: [nos-bbs] UDP Port Unreachable - problem found <o:p></o:p></p><div><p class=MsoNormal style='margin-left:1.0in'>I don't believe you mentioned about two jnos systems behind the same firewall but may be I missed it.<br><br>Why are you not using 44 addresses in your axudp link at both sides?<br><br>Bob<br><br><br>On 13-11-16 09:20 PM, Michael E Fox - N6MEF wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal style='margin-left:1.0in'>No Bob, I'm talking about two JNOS systems behind the same firewall. The firewall has to change the source port of at least the second one on the way out. Otherwise, the destination IP and destination port are all the same on the way back in. I believe I've already mentioned this a couple of times. This is basic firewall connection muxing.<o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'>Sonicwall happens to change the source port all the time, instead of after the first connection. And it works just fine for everything but JNOS. If JNOS behaved like a normal UDP app, it would work fine, too.<o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'>The point is that there is simply no reason to require a specific source port. It's just not the way the UDP world works. And doing so renders the system unworkable when placed behind 10s of 1000s of commercial firewalls.<o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'>The whole point of axudp is so it can be used in situations where axip can't be used. But with this bizarre restriction, it's defeating that purpose.<o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'>M<o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><p class=MsoNormal style='margin-left:1.0in'> <o:p></o:p></p></div><div><div><p class=MsoNormal style='margin-left:1.0in'><span style='font-size:7.0pt;color:#575757'>Sent from my Verizon Wireless 4G LTE smartphone</span><o:p></o:p></p></div></div><p class=MsoNormal style='mso-margin-top-alt:0in;margin-right:0in;margin-bottom:12.0pt;margin-left:1.0in'><br><br>-------- Original message --------<br>From: Bob Tenty <br>Date:11/16/2013 3:38 PM (GMT-08:00) <br>To: TAPR xNOS Mailing List <br>Subject: Re: [nos-bbs] UDP Port Unreachable - problem found <o:p></o:p></p><div><p class=MsoNormal style='margin-left:1.0in'>Michael,<br><br>You are making a thinking error here.<br><br>If I make a link to another jnos system the destination ip number is different.<br>Also the return route from that second jnos system uses another ip number as the first jnos system so there is no problem it all.<br>Even with the same port. It is the combination of ip number + port.<br><br>Those consumer router/firewall boxes are cheaply designed and targeted for the average Joe customer user needs.<br>Install dd-wrt in it if available for it and you will be much happier.<br><br><br>73,<br><br>Bob VE3TOK<br><br><br><br><br><br><br>On 13-11-16 12:35 PM, Michael E. Fox - N6MEF wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal style='margin-left:1.0in'><span style='color:#1F497D'>Yes, Linux leaves the source port alone on the first connection. But that only works for the first JNOS system. Even a firewall that initially leave the source port alone will need to change the source port if a second JNOS system exists so it can track connections to two different machines.</span><o:p></o:p></p><p class=MsoNormal style='margin-left:1.0in'><span style='color:#1F497D'> </span><o:p></o:p></p><p class=MsoNormal style='margin-left:1.0in'><span style='color:#1F497D'>M</span><o:p></o:p></p><p class=MsoNormal style='margin-left:1.0in'><span style='color:#1F497D'> </span><o:p></o:p></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal style='margin-left:1.5in'><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext'> <a href="mailto:nos-bbs-bounces@tapr.org">nos-bbs-bounces@tapr.org</a> [<a href="mailto:nos-bbs-bounces@tapr.org">mailto:nos-bbs-bounces@tapr.org</a>] <b>On Behalf Of </b>Bob Tenty<br><b>Sent:</b> Friday, November 15, 2013 11:37 PM<br><b>To:</b> TAPR xNOS Mailing List<br><b>Subject:</b> Re: [nos-bbs] UDP Port Unreachable - problem found</span><o:p></o:p></p></div></div><p class=MsoNormal style='margin-left:1.5in'> <o:p></o:p></p><div><p class=MsoNormal style='margin-left:1.5in'>Yes, I have seen that with those boxes. That is why I always replace the firmware with linux when possible.<br><br>Bob<br><br><br>On 13-11-16 01:33 AM, Michael E. Fox - N6MEF wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal style='margin-left:1.5in'>I found the problem with the UDP port 93 unreachable message: JNOS is (incorrectly) requiring the source port to also be 93 in AXUDP connections.<o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'> <o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'>When I connect outbound from my JNOS system, through my firewall, the firewall is changing the source port when it performs the outbound NAT. But this is normal for a firewall. In fact, it HAS to do this if it’s going to allow for multiple connects of the same protocol from different machines. Many consumer-grade firewalls will leave the source port alone for the first connection (if it’s not already in use) and only change it for subsequent connections. SonicWall is a bit more strict, frequently changing the source port, making it harder for intercepted packets to be tracked to any one machine.<o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'> <o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'>Normally, this doesn’t matter. Applications/services listen on a particular port and respond to whatever incoming connections use that *<b>destination</b>* port. They don’t care what the source port is. Firewalls then use different source ports to track multiple conversations so that when the packets return, all addressed to the same external NAT address, it can direct them to the proper place by the port number.<o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'> <o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'>But when JNOS receives an AXUDP packet, apparently it doesn’t behave like a normal UDP application. JNOS apparently rejects the connection if the *<b>source</b>* port is not 93, even if the destination port is correctly set to 93. This is unusual, to say the least. But even worse, it issues an ICMP “udp port 93 unreachable” message which is completely wrong, since port 93 is definitely reachable.<o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'> <o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'>It seems the following is needed: Remove the source port restriction for AXUDP. JNOS should not care what the source port is. And, just like any other UDP app, when responding it should use whatever source port was specified as the destination port when it constructs the return packet.<o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'> <o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'>Michael<o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'>N6MEF<o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'> <o:p></o:p></p><p class=MsoNormal style='margin-left:1.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><br><br><br><br><br></span><o:p></o:p></p><pre style='margin-left:1.5in'>_______________________________________________<o:p></o:p></pre><pre style='margin-left:1.5in'>nos-bbs mailing list<o:p></o:p></pre><pre style='margin-left:1.5in'><a href="mailto:nos-bbs@tapr.org">nos-bbs@tapr.org</a><o:p></o:p></pre><pre style='margin-left:1.5in'><a href="http://www.tapr.org/mailman/listinfo/nos-bbs">http://www.tapr.org/mailman/listinfo/nos-bbs</a><o:p></o:p></pre></blockquote><p class=MsoNormal style='margin-left:1.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> </span><o:p></o:p></p><p class=MsoNormal style='margin-left:1.0in'><span style='font-size:12.0pt;font-family:"Times New Roman , serif","serif"'><br><br><br><br></span><o:p></o:p></p><pre style='margin-left:1.0in'>_______________________________________________<o:p></o:p></pre><pre style='margin-left:1.0in'>nos-bbs mailing list<o:p></o:p></pre><pre style='margin-left:1.0in'><a href="mailto:nos-bbs@tapr.org">nos-bbs@tapr.org</a><o:p></o:p></pre><pre style='margin-left:1.0in'><a href="http://www.tapr.org/mailman/listinfo/nos-bbs">http://www.tapr.org/mailman/listinfo/nos-bbs</a><o:p></o:p></pre></blockquote><p class=MsoNormal style='margin-left:1.0in'><span style='font-size:12.0pt;font-family:"Times New Roman , serif","serif"'><br><br><br></span><o:p></o:p></p></blockquote><p class=MsoNormal style='margin-left:1.0in'><span style='font-size:12.0pt;font-family:"Times New Roman , serif","serif"'> </span><o:p></o:p></p></blockquote><p class=MsoNormal style='margin-left:1.0in'><span style='font-size:12.0pt;font-family:"Times New Roman , serif","serif"'> </span><o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><br><br><br><o:p></o:p></span></p><pre style='margin-left:.5in'>_______________________________________________<o:p></o:p></pre><pre style='margin-left:.5in'>nos-bbs mailing list<o:p></o:p></pre><pre style='margin-left:.5in'><a href="mailto:nos-bbs@tapr.org">nos-bbs@tapr.org</a><o:p></o:p></pre><pre style='margin-left:.5in'><a href="http://www.tapr.org/mailman/listinfo/nos-bbs">http://www.tapr.org/mailman/listinfo/nos-bbs</a><o:p></o:p></pre></blockquote><p class=MsoNormal style='margin-left:.5in'><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p></div></body></html>