<div><font size="5">Hi </font></div><div><font size="5"><br /></font></div><div><font size="5">I am not sure this is the right forum but most of you folks are experts in DNS and maybe able to help. My apologies</font></div><div><font size="5"><br /></font></div><div><font size="5">We are doing some experimentation on the behavior of the DNS response to queries by simulating a few thousand devices in containers. </font></div><div><font size="5"><br /></font></div><div><font size="5">When we send AAAA queries from about 3000 devices (each running on docker containers with unique global unicast IPv6 addresses) continuously to the authoritative name server, we have observed the following</font></div><div><font size="5"><br /></font></div><div><pre class="gmail-code gmail-highlight" lang="plaintext" style="border: 0pt; padding: 0pt; background-image: none; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; line-height: 2.8ex; white-space: pre-wrap; overflow-wrap: break-word;"><font size="5"><span class="gmail-line" id="gmail-LC1" lang="plaintext" style="">26-Sep-2019 13:47:47.217 socket.c:1739: unexpected error:</span>
<span class="gmail-line" id="gmail-LC2" lang="plaintext" style="">26-Sep-2019 13:47:47.217 internal_send: 2405:8a00:4001:17:cf69::ce#43084: Invalid argument</span>
<span class="gmail-line" id="gmail-LC3" lang="plaintext" style="">26-Sep-2019 13:47:47.217 client @0x7f03ac352da0 2405:8a00:4001:17:cf69::ce#43084 (<a href="http://7e60e9fc93458393e43e0c23985203bfd0d6627420289a8f9c863771.iith.ipv6.ernet.in/" style="" target="_blank">7e60e9fc93458393e43e0c23985203bfd0d6627420289a8f9c863771.iith.ipv6.ernet.in</a>): error sending response: invalid file</span>
</font></pre></div><div><font size="5">Output logged in the rndc shows that there were <strong>704326 UDP/IPv6 send errors:</strong></font></div><div><b><br /></b></div><div><pre class="gmail-code gmail-highlight" lang="plaintext" style="border: 0pt; padding: 0pt; background-image: none; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; line-height: 2.8ex; white-space: pre-wrap; overflow-wrap: break-word;"><font size="5"><span class="gmail-line" id="gmail-LC1" lang="plaintext" style="">++ Name Server Statistics ++</span>
<span class="gmail-line" id="gmail-LC2" lang="plaintext" style=""> 2520563 IPv6 requests received</span>
<span class="gmail-line" id="gmail-LC3" lang="plaintext" style=""> 2520563 responses sent</span>
<span class="gmail-line" id="gmail-LC4" lang="plaintext" style=""> 2520563 queries resulted in successful answer</span>
<span class="gmail-line" id="gmail-LC5" lang="plaintext" style=""> 2520563 queries resulted in authoritative answer</span>
<span class="gmail-line" id="gmail-LC6" lang="plaintext" style=""> 2520563 UDP queries received</span></font><span style="font-size: 2.5ex;">
</span></pre><pre class="gmail-code gmail-highlight" lang="plaintext" style="border: 0pt; padding: 0pt; background-image: none; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; line-height: 2.8ex; white-space: pre-wrap; overflow-wrap: break-word;"><span class="gmail-line" lang="plaintext" style=""><pre class="gmail-code gmail-highlight" lang="plaintext" style="font-size: 2.5ex; border: 0pt; padding: 0pt; background-image: none; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; line-height: 2.8ex; white-space: pre-wrap; overflow-wrap: break-word;"><span class="gmail-line" id="gmail-LC1" lang="plaintext">++ Socket I/O Statistics ++</span>
<span class="gmail-line" id="gmail-LC2" lang="plaintext"> 157 UDP/IPv4 sockets opened</span>
<span class="gmail-line" id="gmail-LC3" lang="plaintext"> 97 UDP/IPv6 sockets opened</span>
<span class="gmail-line" id="gmail-LC4" lang="plaintext"> 2 TCP/IPv4 sockets opened</span>
<span class="gmail-line" id="gmail-LC5" lang="plaintext"> 38 TCP/IPv6 sockets opened</span>
<span class="gmail-line" id="gmail-LC6" lang="plaintext"> 1 Raw sockets opened</span>
<span class="gmail-line" id="gmail-LC7" lang="plaintext"> 102 UDP/IPv4 sockets closed</span>
<span class="gmail-line" id="gmail-LC8" lang="plaintext"> 42 UDP/IPv6 sockets closed</span>
<span class="gmail-line" id="gmail-LC9" lang="plaintext"> 137 TCP/IPv6 sockets closed</span>
<span class="gmail-line" id="gmail-LC10" lang="plaintext"> 102 UDP/IPv4 socket connect failures</span>
<span class="gmail-line" id="gmail-LC11" lang="plaintext"> 41 UDP/IPv6 connections established</span>
<span class="gmail-line" id="gmail-LC12" lang="plaintext"> 35 TCP/IPv6 connections established</span>
<span class="gmail-line" id="gmail-LC13" lang="plaintext"> 1 TCP/IPv4 connections accepted</span>
<span class="gmail-line" id="gmail-LC14" lang="plaintext"> 102 TCP/IPv6 connections accepted</span>
<span class="gmail-line" id="gmail-LC15" lang="plaintext"> 102 UDP/IPv4 send errors</span>
<span class="gmail-line" id="gmail-LC16" lang="plaintext"> 704326 UDP/IPv6 send errors</span>
<span class="gmail-line" id="gmail-LC17" lang="plaintext"> 46 TCP/IPv6 send errors</span>
<span class="gmail-line" id="gmail-LC18" lang="plaintext"> 1 TCP/IPv6 recv errors</span>
<span class="gmail-line" id="gmail-LC19" lang="plaintext"> 55 UDP/IPv4 sockets active</span>
<span class="gmail-line" id="gmail-LC20" lang="plaintext"> 55 UDP/IPv6 sockets active</span>
<span class="gmail-line" id="gmail-LC21" lang="plaintext"> 3 TCP/IPv4 sockets active</span>
<span class="gmail-line" id="gmail-LC22" lang="plaintext"> 3 TCP/IPv6 sockets active</span>
<span class="gmail-line" id="gmail-LC23" lang="plaintext"> 1 Raw sockets active</span></pre><pre class="gmail-code gmail-highlight" lang="plaintext" style="border: 0pt; padding: 0pt; background-image: none; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; line-height: 2.8ex; white-space: pre-wrap; overflow-wrap: break-word;"><font size="5">Used BIND 9.14.6 (Stable Release) <id:efd3496></font></pre><pre class="gmail-code gmail-highlight" lang="plaintext" style="font-size: 2.5ex; border: 0pt; padding: 0pt; background-image: none; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; line-height: 2.8ex; white-space: pre-wrap; overflow-wrap: break-word;"><span class="gmail-line" id="gmail-LC2" lang="plaintext">running on Linux x86_64 4.15.0-64-generic #73~16.04.1-Ubuntu SMP Fri Sep 13 09:56:18 UTC 2019</span>
<span class="gmail-line" id="gmail-LC3" lang="plaintext">built by make with '--with-libxml2'</span>
<span class="gmail-line" id="gmail-LC4" lang="plaintext">compiled by GCC 5.4.0 20160609</span>
<span class="gmail-line" id="gmail-LC5" lang="plaintext">compiled with OpenSSL version: OpenSSL 1.0.2g 1 Mar 2016</span>
<span class="gmail-line" id="gmail-LC6" lang="plaintext">linked to OpenSSL version: OpenSSL 1.0.2g 1 Mar 2016</span>
<span class="gmail-line" id="gmail-LC7" lang="plaintext">compiled with libxml2 version: 2.9.3</span>
<span class="gmail-line" id="gmail-LC8" lang="plaintext">linked to libxml2 version: 20903</span>
<span class="gmail-line" id="gmail-LC9" lang="plaintext">compiled with zlib version: 1.2.8</span>
<span class="gmail-line" id="gmail-LC10" lang="plaintext">linked to zlib version: 1.2.8</span>
<span class="gmail-line" id="gmail-LC11" lang="plaintext">threads support is enabled</span>
<span class="gmail-line" id="gmail-LC12" lang="plaintext"></span>
<span class="gmail-line" id="gmail-LC13" lang="plaintext">default paths:</span>
<span class="gmail-line" id="gmail-LC14" lang="plaintext"> named configuration: /etc/named.conf</span>
<span class="gmail-line" id="gmail-LC15" lang="plaintext"> rndc configuration: /etc/rndc.conf</span>
<span class="gmail-line" id="gmail-LC16" lang="plaintext"> DNSSEC root key: /etc/bind.keys</span>
<span class="gmail-line" id="gmail-LC17" lang="plaintext"> nsupdate session key: /var/run/named/session.key</span>
<span class="gmail-line" id="gmail-LC18" lang="plaintext"> named PID file: /var/run/named/named.pid</span>
<span class="gmail-line" id="gmail-LC19" lang="plaintext"> named lock file: /var/run/named/named.lock</span>
</pre><pre class="gmail-code gmail-highlight" lang="plaintext" style="font-size: 2.5ex; border: 0pt; padding: 0pt; background-image: none; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; line-height: 2.8ex; white-space: pre-wrap; overflow-wrap: break-word;"><span class="gmail-line" lang="plaintext">I searched and found that similar issue has been raised previously and were claimed to have been fixed. I also observe that the suggested fix has been incorporated in the current BIND 14. However the error remains.</span></pre><pre class="gmail-code gmail-highlight" lang="plaintext" style="font-size: 2.5ex; border: 0pt; padding: 0pt; background-image: none; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; line-height: 2.8ex; white-space: pre-wrap; overflow-wrap: break-word;"><span class="gmail-line" lang="plaintext">We have already raised this issue with ISC also but was wondering if someone in this forum came across this issue or can throw some insight to the probable cause of the error and provide some suggestions to solve this issue.</span></pre></span></pre></div><div><font size="5">-- <br signature="separator" /></font><div><font size="5">Regards <span class="Apple-tab-span" style="white-space: pre;"> </span> भवदीय <br />Praveen Misra <span class="Apple-tab-span" style="white-space: pre;"> </span> प्रवीण मिस्र <br />Addl. Director (IPv6, AI & Accessibility) , अतिरिक्त निदेशक (IPv6, कृत्रिम बुद्धिमत्ता एवं सुगमता)</font></div><h3 class="r" style="font-weight: normal; margin: 0px; padding: 0px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; color: rgb(34, 34, 34); font-family: arial, sans-serif; background-color: rgb(255, 255, 255);"><font size="5">ERNET India <span class="Apple-tab-span" style="background-color: transparent; white-space: pre;"> </span> <span style="background-color: transparent;"> ई॰आर॰नेट इंडिया</span></font></h3><div><font size="5">(Ministry of Electronics & IT, Govt of India) (इलेक्ट्रॉनिक्स एवं सूचना प्रद्योगिकी मंत्रालय, भारत सरकार)<br />6, CGO Complex,Lodhi Road <span class="Apple-tab-span" style="white-space: pre;"> </span> 6 सी॰जी॰ओ कॉम्प्लेक्स, लोदी रोड<br />New Delhi-110003 India <span class="Apple-tab-span" style="white-space: pre;"> </span> नई दिल्ली, 110003, इंडिया॰<br />Phone: +91-11-22170595 <span class="Apple-tab-span" style="white-space: pre;"> </span> दूरभाष: +91-11-22170595<br />Mobile: +91-98189 55800 <span class="Apple-tab-span" style="white-space: pre;"> </span> मोबाइल: +91-9818955800<br />Skype: misrapraveen<span style="white-space:pre"> </span> www.ipv6.ernet.in</font></div><div><br /></div><div><font size="5"><br /><br /></font></div></div>