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<p>Thanks Simon. Appreciate the heads-up on the off-topic parts of my post.<br /><br />I see from the auth.log entries that dhcp_release is being called as:<br /><br /> dhcp_release tapc5399cce-70 132.16.0.13 fa:16:3e:8e:83:97<br /><br />To me that looks good, and lines up with the man page for dhcp_release. The interface "tapc5399cce-70" is the same as in the dnsmasq-dhcp log entries for the request and offer, and also matches the output of:<br /><br /> ip netns exec qdhcp-34705fcf-4f9c-48eb-b0bc-ac5091e181c8 ip a</p>
<p>I will try to reproduce again and watch the tcpdump for the release packet. <br /><br />Thanks,<br />GP</p>
<p>On 2017-05-17 14:39, Simon Kelley wrote:</p>
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<div class="pre" style="margin: 0; padding: 0; font-family: monospace">Ah, didn't read this before my previous reply.<br /><br /> dhcp_release is getting called, but dnsmasq is not getting the packet<br /> (dhcp_release works by faking up a DHCP message as if it's coming from<br /> the DHCP client, which tells the server to release the lease.)<br /><br /> If you can't see the packet in your packet dump, then that's significant.<br /><br /> Note that dhcp_release needs an "interface" parameter. That has to be<br /> correct.<br /><br /> Cheers,<br /><br /> Simon.<br /><br /><br /><br /><br /> On 17/05/17 19:12, Graeme Peterson wrote:
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0">I found the following entry in /var/log/auth.log which shows neutron as<br /> root (sudo) calling dhcp_release on IP: 132.16.0.13, MAC: <br /> fa:16:3e:8e:83:97 two minutes after the DHCPACK and two minutes before<br /> the dnsmasq-dhcp log failure saying: "not using configured address<br /> 132.16.0.13 because it is leased to fa:16:3e:8e:83:97". Looks to me like<br /> Openstack is calling dhcp_release correctly. The dnsmask log is in a<br /> folder named "34705fcf-4f9c-48eb-b0bc-ac5091e181c8", same as the arg to<br /> ip netns exec without the "qdhcp-" prefix. So far it looks like a<br /> dhcp_release/dnsmasq issue to my untrained eye. I have been able to work<br /> around it somewhat by setting the max lease time to 30 seconds, although<br /> that seems to be introducing other issues, more investigation required<br /> there.<br /><br /> ./auth.log:May 16 16:55:21 my-ucs-69 sudo: neutron : TTY=unknown ;<br /> PWD=/var/lib/neutron ; USER=root ; COMMAND=/usr/bin/neutron-rootwrap<br /> /etc/neutron/rootwrap.conf ip netns exec<br /> qdhcp-34705fcf-4f9c-48eb-b0bc-ac5091e181c8 dhcp_release tapc5399cce-70<br /> 132.16.0.13 fa:16:3e:8e:83:97<br /><br /> Thanks again,<br /> Graeme<br /><br /> On 2017-05-17 12:24, Graeme Peterson wrote:<br /><br />
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0">Hi all.<br /><br /> Sorry if this issue has been discussed and resolved, I am new to the<br /> list. I tried to find it in the list, and came across this reference<br /> to the issue from Jan 2016:<br /><br /><a href="http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2016q1/010273.html">http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2016q1/010273.html</a><br /><br /><br /> What I am seeing is with OpenStack Newton on Ubuntu 16.10<br /> (4.8.0-49-generic), with force_dhcp_release=True in<br /> /etc/nova/nova.conf, using tcpdump on the netns for the relevant<br /> Openstack network, I see dnsmasq receives the dhcp request, issues an<br /> IP, and that IP should be released (Openstack should be calling<br /> dhcp_release, I need to figure out how to verify that it is or is not<br /> happening, however force_dhcp_release=True is explicitly set in<br /> /etc/nova/nova.conf) , but it seems like the dhcp entry isn't being<br /> entirely released. The odd thing is that when a new VM wants an IP,<br /> tcpdump shows the request coming in for an address, but no reply, and<br /> OpenStack thinks it got an IP - the same one that used to belong to<br /> the recently terminated VM - but there is no dhcp offer in the<br /> tcpdump, and the dnsmasq log shows:<br /><br /> May 16 16:53:15 dnsmasq-dhcp[40394]: 3306068020<br /> DHCPREQUEST(tapc5399cce-70) 132.16.0.13 fa:16:3e:8e:83:97<br /> May 16 16:53:15 dnsmasq-dhcp[40394]: 3306068020 tags: tag0, known,<br /> tapc5399cce-70<br /> May 16 16:53:15 dnsmasq-dhcp[40394]: 3306068020<br /> DHCPACK(tapc5399cce-70) 132.16.0.13 fa:16:3e:8e:83:97 host-132-16-0-13<br /> ...<br /> ...<br /> ...<br /> May 16 16:57:12 dnsmasq-dhcp[40394]: 461988430 available DHCP subnet:<br /> 132.16.0.0/255.255.0.0<br /> May 16 16:57:12 dnsmasq-dhcp[40394]: not using configured address<br /> 132.16.0.13 because it is leased to fa:16:3e:8e:83:97<br /> May 16 16:57:12 dnsmasq-dhcp[40394]: 461988430<br /> DHCPDISCOVER(tapc5399cce-70) 192.168.0.51 fa:16:3e:31:de:d3 no address<br /> available<br /><br /> I don't see a log entry for a release of 132.16.0.13, not sure if<br /> there should be one.<br /><br /><br /> Is this a known and hopefully fixed issue? Can I provide further info<br /> to help investigate it?<br /><br /> Thanks,<br /> Graeme<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 /> <mailto:<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">http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss</a></blockquote>
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