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</o:shapelayout></xml><![endif]--></head><body lang=RU link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>Hi Kevin,<br><br>Ignoring all naks – would be, but the fix is different.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'>That fix ignores all naks except from the selected/requested server only, it’s ok.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:10.0pt;font-family:"Arial Narrow",sans-serif;color:#1F497D'>Best Regards, Vladislav Grishenko<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><div style='border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt'><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri",sans-serif'> Kevin </span><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>Benton [mailto:blak111@gmail.com] <br><b>Sent:</b> Wednesday, May 27, 2015 9:32 AM<br><b>To:</b> Vladislav Grishenko<br><b>Cc:</b> Brian Haley; Simon Kelley; dnsmasq-discuss@lists.thekelleys.org.uk<br><b>Subject:</b> Re: [Dnsmasq-discuss] Query about solving a DHCPNAK issue<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>That fix is interesting. Doesn't ignoring a NAK sort of defeat the point of the 'authoritative' NAKing in the first place?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>On Tue, May 26, 2015 at 2:26 PM, Vladislav Grishenko <<a href="mailto:themiron@mail.ru" target="_blank">themiron@mail.ru</a>> wrote:<o:p></o:p></p><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0cm 0cm 0cm 6.0pt;margin-left:4.8pt;margin-right:0cm'><div><div><p class=MsoNormal style='margin-bottom:12.0pt'>> On 02/02/2015 05:47 PM, Brian Haley wrote:<br>> >><br>> >>> The one thing I'm curious about is if dnsmasq is restarted while a<br>> >>> VM holds a lease, how will it respond? As someone else has<br>> >>> pointed-out to me - isc-dhcp will respond with a DHCPNAK in that<br>> >>> case, and wondered why there would be a difference with dnsmasq.<br>> >>> Different interpretation of an RFC?<br>> >><br>> >><br>> >> If by "dnsmasq is restarted" you mean "dnsmasq is restarted and<br>> >> therefore has its lease database deleted", then the RFC says that if<br>> >> a server gets a renewal for an unknown lease, it should return<br>> >> DHCPNAK. That's what dnsmasq does _unless_ --dhcp-authoritative is<br>> >> set, when instead it quietly re-creates the lease.<br>> ><br>> > Yes, your assumption is correct, as --leasefile-ro is used it knows of<br>> > no current leases, and by default get a DHCPNAK.<br>> ><br>> >> dhcp-authoritative gives permission to dnsmasq to violate the RFC in<br>> >> a way which is useful in certain circumstances.<br>> ><br>> > Thanks, it does seem to do what I want with my initial testing.<br>><br>> Hi Simon,<br>><br>> Replying to my old thread since using --dhcp-authoritative seems to have<br>> introduced an issue where a DHCP client can get a NAK when using multiple<br>> dnsmasq servers on the same subnet (they both have the same host<br>> information, >1 running just to get HA).<br>><br>> Short story is that both dnsmasq's return the same lease info, but when<br>the<br>> client ACKs (sending to broadcast), one agent ACKs and the other agent<br>> NAKs.<br>> The tcpdump shows this better than I'm describing:<br>><br>> <a href="https://launchpadlibrarian.net/207180476/dhcp_neutron_bug.html" target="_blank">https://launchpadlibrarian.net/207180476/dhcp_neutron_bug.html</a><br>><br>> Does that seem like normal operation to you? Does this second dnsmasq<br>> assume this response is from a rogue server and NAKs since it didn't send<br>out<br>> the offer?<br>><o:p></o:p></p></div></div><p class=MsoNormal>Hi Brian,<br><br>Second dnsmasq assume the client request is to another server and responds<br>with NAK in authoritative mode.<br>The root of loop issue is in that busybox 1.20.x udhcpc client, it doesn't<br>check server id for anything but offer packet.<br>Bug is already fixed in bb 1.23.x, see commit<br><a href="http://git.busybox.net/busybox/commit/?id=e2318bbad786d6f9ebff704490246bfe52e588c0" target="_blank">http://git.busybox.net/busybox/commit/?id=e2318bbad786d6f9ebff704490246bfe52<br>e588c0</a><br><br>Best Regards, Vladislav Grishenko<o:p></o:p></p><div><div><p class=MsoNormal><br><br><br>_______________________________________________<br>Dnsmasq-discuss mailing list<br><a href="mailto:Dnsmasq-discuss@lists.thekelleys.org.uk">Dnsmasq-discuss@lists.thekelleys.org.uk</a><br><a href="http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss" target="_blank">http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss</a><o:p></o:p></p></div></div></blockquote></div><p class=MsoNormal><br><br clear=all><o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><p class=MsoNormal>-- <o:p></o:p></p><div><div><p class=MsoNormal>Kevin Benton<o:p></o:p></p></div></div></div></div></div></body></html>