<div dir="ltr"><div><div>Hello,</div><div><br></div><div>I am tracing an issue where <span class="gmail-il">dnsmasq</span> 2.86 appears to get stuck in a loop using all compute resources for the core it's on, and becomes unresponsive to DHCP4, DHCPv6 and DNS requests.  I am working on replicating the problem, and want to check to see if anyone on this list has seen the behavior before -- </div><div><br></div><div>-- Details -- </div><div><br></div><div>On the local LAN I am seeing 3 devices in DHCPv6 that are requesting IPV6 addresses every 10 minutes, even though their expiry time is advertised as 8 hours. I will have some difficulty finding the exact devices.  It appears the DHCPv6 lease file continues tracking all of the leases on this openwrt based router.</div><div><br></div><div>A subset of these tracked requests are here, from the lease file -</div><div><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740156067 1484488511 2600:4040:a92e:2700::ffcd * 00:03:00:01:f0:09:0d:cb:26:08</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740156067 1484488511 fd30:fc9a:a298::f8a3 * 00:03:00:01:f0:09:0d:cb:26:08</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><br></span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740156067 1375367042 2600:4040:a92e:2700::ffcc * 00:03:00:01:f0:09:0d:cb:27:52</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740156067 1375367042 fd30:fc9a:a298::f8a2 * 00:03:00:01:f0:09:0d:cb:27:52</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><br></span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740155562 1744997917 2600:4040:a92e:2700::ffcb * 00:03:00:01:f0:09:0d:cb:26:08</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740155562 1744997917 fd30:fc9a:a298::f8a1 * 00:03:00:01:f0:09:0d:cb:26:08</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><br></span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740155561 729442040 2600:4040:a92e:2700::ffca * 00:03:00:01:f0:09:0d:cb:27:52</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740155561 729442040 fd30:fc9a:a298::f8a0 * 00:03:00:01:f0:09:0d:cb:27:52</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><br></span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740155561 1831382606 2600:4040:a92e:2700::ffc9 * 00:03:00:01:f0:09:0d:cb:25:b0</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740155561 1831382606 fd30:fc9a:a298::f89f * 00:03:00:01:f0:09:0d:cb:25:b0</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><br></span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740155018 995327705 2600:4040:a92e:2700::ffc8 * 00:03:00:01:f0:09:0d:cb:25:b0</span></p><p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;font-size-adjust:none;font-kerning:auto;font-feature-settings:normal;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">1740155018 995327705 fd30:fc9a:a298::f89e * 00:03:00:01:f0:09:0d:cb:25:b0</span></p></div><div><br></div><div><br></div><div>So, this is 48 entries (identical) in the dhcpv6 lease file per host that does this.  There are 2 entries, per host (96 entries) .. and there are 3 hosts on the LAN doing this -- bringing the entries to 288 tracked leases, excluding the IPV4 leases too.</div><div><br></div><div>My <span class="gmail-il">dnsmasq</span> config file is attached ( <span class="gmail-il">dnsmasq</span>-configfile.txt ).  The only parameter I imagine is related :</div><div><br></div><div>   dhcp-range=set:lan,192.168.2.40,192.168.2.254,255.255.255.0,8h</div><div><br></div><div>Notably - this is not a DHCPv6 setting, but it <b>does </b>show the 8h lease time I am seeing in the DHCPv6 leases , AND the parameters here have a limit of 215 addresses these hosts are pushing (the same) number of leases over 288 within an 8hour span.</div><div><br></div><div>Has anyone seen this before ?  Why are the IPv6 leases not replaced in the lease file when the same DUID requests addresses well before the end of the IPv6 lease time ?</div><div><br></div><div><br></div><div>*Bonus* -- I've attached a pcap file for the DHCPv6 requests I think could be central to this problem.  These packets arrived much later of course, well after I've experienced this problem, but may give us some insight to what's happening.</div><div><br></div><div><br></div><div>Thank you,</div><div><div dir="ltr" class="gmail_signature">Bryant Eadon</div></div></div></div><div hspace="streak-pt-mark" style="max-height:1px"><img alt="" style="width:0px;max-height:0px;overflow:hidden" src="https://mailfoogae.appspot.com/t?sender=aYnJ5YW50LmVhZG9uQGdtYWlsLmNvbQ%3D%3D&type=zerocontent&guid=614ec00b-1bf5-4313-91b7-90d89013ea0e"><font color="#ffffff" size="1">ᐧ</font></div>