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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-US link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span style='color:windowtext'>Can you share this solution of yours?<o:p></o:p></span></p><p class=MsoNormal><span style='color:windowtext'>These days it’s good to know about any piece of IPv4 vs/with IPv6 stack solutions.<o:p></o:p></span></p><p class=MsoNormal><span style='color:windowtext'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:windowtext'>Eliezer<o:p></o:p></span></p><p class=MsoNormal><span style='color:windowtext'><o:p> </o:p></span></p><div><p class=MsoNormal><span style='color:windowtext'>----<o:p></o:p></span></p><p class=MsoNormal><span style='color:windowtext'>Eliezer Croitoru<o:p></o:p></span></p><p class=MsoNormal><span style='color:windowtext'>Tech Support<o:p></o:p></span></p><p class=MsoNormal><span style='color:windowtext'>Mobile: +972-5-28704261<o:p></o:p></span></p><p class=MsoNormal><span style='color:windowtext'>Email: <a href="mailto:ngtech1ltd@gmail.com">ngtech1ltd@gmail.com</a><o:p></o:p></span></p><p class=MsoNormal><span style='color:windowtext'>Zoom: Coming soon<o:p></o:p></span></p><p class=MsoNormal><span style='color:windowtext'><o:p> </o:p></span></p></div><p class=MsoNormal><span style='color:windowtext'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='color:windowtext'>From:</span></b><span style='color:windowtext'> squid-users <squid-users-bounces@lists.squid-cache.org> <b>On Behalf Of </b>Walter H.<br><b>Sent:</b> Tuesday, January 12, 2021 7:24 PM<br><b>To:</b> squid-users@lists.squid-cache.org<br><b>Subject:</b> Re: [squid-users] distinguish between IPv4 and IPv6<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Hello,<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>I did something different, that prevents using the IPv6 of the tunnel device als source address;<o:p></o:p></p></div><div><p class=MsoNormal>(a general solution not just squid)<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Walter<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>On 11.01.2021 21:29, Eliezer Croitoru wrote:<o:p></o:p></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The detection of an IPV6 available DST can be determined by DNS and external ACL helper.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>It will “slow” down the first couple bytes of the connection but can be much more reliable then the basic “dst” acl.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The basic test would be something like:<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>nslookup -type=aaaa <a href="http://www.squid-cache.org">www.squid-cache.org</a> -timeout=10 |grep -v '#53'|grep Address:|wc -l<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>if the wc -l gt 0 then try to use IPV6.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I believe it’s pretty simple and the main issue is that if a service advertises unreachable IPV6 address.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>It can be either because of network misconfiguration or FW or misconfigured DNS.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I have seen all of the above happen in production services in the last year.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I can write a helper for this if required.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Eliezer<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>----<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Eliezer Croitoru<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Tech Support<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Mobile: +972-5-28704261<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Email: <a href="mailto:ngtech1ltd@gmail.com">ngtech1ltd@gmail.com</a><o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Zoom: Coming soon<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><b>From:</b> squid-users <a href="mailto:squid-users-bounces@lists.squid-cache.org"><squid-users-bounces@lists.squid-cache.org></a> <b>On Behalf Of </b>?Amos Jeffries?<br><b>Sent:</b> Monday, January 11, 2021 10:10 PM<br><b>To:</b> Walter H. <a href="mailto:Walter.H@mathemainzel.info"><Walter.H@mathemainzel.info></a>; <a href="mailto:squid-users@lists.squid-cache.org">squid-users@lists.squid-cache.org</a><br><b>Subject:</b> Re: [squid-users] distinguish between IPv4 and IPv6<o:p></o:p></p></div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The dst ACL type accepts the special value of "ipv4". You can use that and the "!" operator to split traffic.<o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>However, please be aware dst is not very reliable until *after* the outgoing connection has been created, and we are still finding some access checks that do not use it correctly. YMMV.<o:p></o:p></p><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Amos<o:p></o:p></p></div></div></div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><br>-------- Original message --------<br>From: "Walter H."<br>Date: Tue, 12 Jan 2021, 03:19<o:p></o:p></p><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Hello,<br><br>is there a way, that I can do something like<br><br>if ( dst is IPv4 ) go direct<br>if ( dst is IPv6 ) use parent proxy xxx<br><br>The reason for my question, I'm using a IPv6-in-IPv4 tunnel,<br>and it would make sense to forward all traffic going to IPv6 to squid <br>running on tunnel end;<br><br>Thanks,<br>Walter<o:p></o:p></p></blockquote></div></div></blockquote><p class=MsoNormal><o:p> </o:p></p></div></body></html>