<div dir="ltr"><div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)" class="gmail_default">We tried 9.18.48 (latest of 9.18.x) also crashed with the same error within a couple of minutes. We will perform another upgrade to version 9.20.22 and see what happens.</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)" class="gmail_default"><br></div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)" class="gmail_default">Is the "recursion loop detected" message in the logs considered normal when stale serve is enabled? or is it happening due to misconfiguration?</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)" class="gmail_default"><br></div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)" class="gmail_default">Best regards </div><br></div><div><br></div><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Sun, 3 May 2026 at 10:54, Ondřej Surý <<a href="mailto:ondrej@isc.org">ondrej@isc.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="auto"><div dir="ltr">You are running outdated version - <span style="color:rgb(7,55,99);font-family:tahoma,sans-serif;background-color:rgb(255,255,255)">BIND 9.18.41, first step would be to upgrade to latest 9.18 version or even better to latest 9.20 as BIND 9.18 will reach end of life quite soon.</span><div><font color="#073763" face="tahoma, sans-serif"><span style="background-color:rgb(255,255,255)"><br></span></font></div><div><font color="#073763" face="tahoma, sans-serif"><span style="background-color:rgb(255,255,255)">Ondrej</span></font></div><div><div dir="ltr"><span style="background-color:rgba(255,255,255,0)">--<br>Ondřej Surý (He/Him)<br><span dir="ltr"><a href="mailto:ondrej@isc.org" target="_blank">ondrej@isc.org</a></span><br><br>ADHD brain at work: I sometimes lose track of my inbox. Please feel free to send a gentle nudge if you're waiting on a reply!<br><br>My working hours and your working hours may be different. Please do not feel obligated to reply outside your normal working hours.</span><br style="font-size:17px"></div><div dir="ltr"><br><blockquote type="cite">On 3. 5. 2026, at 9:40, Ibrahim Almahfooz <<a href="mailto:ibrahim.nezar@sevennet.net" target="_blank">ibrahim.nezar@sevennet.net</a>> wrote:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><div dir="ltr"><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)">Hi,</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)"><br></div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)">Recently we have enabled stale serve on our recursive BIND 9.18.41 (Extended Support Version), the service crashes after a few minutes, showing the following lines inside the log files:</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)"><br></div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)">*Sample from named.run logs showing the recursion loop:</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)">03-May-2026 07:37:41.553 client: info: client @0x7f32d0d4c498 10.40.153.193#14013 (<a href="http://api.al-array.com" target="_blank">api.al-array.com</a>): view our-users: recursion loop detected<br>03-May-2026 07:37:41.553 client: info: client @0x7f32d0993c98 10.36.16.177#10683 (<a href="http://api.al-array.com" target="_blank">api.al-array.com</a>): view our-users: recursion loop detected<br>03-May-2026 07:37:41.702 client: info: client @0x7f32d0da7098 10.36.24.213#47838 (<a href="http://ninja12002.serv00.net" target="_blank">ninja12002.serv00.net</a>): view our-users: recursion loop detected<br>03-May-2026 07:37:41.717 client: info: client @0x7f32d25e4098 10.48.72.221#37292 (<a href="http://hayward.walsivrtgam.net" target="_blank">hayward.walsivrtgam.net</a>): view our-users: recursion loop detected</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)"><br></div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)">*Sample from default logs showing the assertion failure:
</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)">default.1:03-May-2026 07:38:30.213 general: critical: /opt/isc/isc-bind/root/usr/lib64/<a href="http://libisc-9.18.41.so" target="_blank">libisc-9.18.41.so</a>(isc_assertion_failed+0xe) [0x7f32d615538e]<br>default.1:03-May-2026 07:38:30.213 general: critical: exiting (due to assertion failure)</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)"><br></div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)">*Our resolver is receiving around 20k QPS.</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)"><br></div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)">*Below is the configuration<br>## Global Named Configuration<br>options {<br> directory "/var/opt/isc/scls/isc-bind/named/data";<br> listen-on { 127.0.0.1; 192.168.20.2; };<br> allow-transfer {"none";};<br> dnssec-validation auto;<br> querylog no;<br> recursive-clients 10000;<br> dnstap {all;};<br> dnstap-output file "named-logs/dnstap.file";<br> dnstap-identity "<a href="http://ns02.ourdomain.net" target="_blank">ns02.ourdomain.net</a>";<br> deny-answer-addresses { deny-answer-referral-acl; };<br>};<br><br># For monitoring systems to fetch named statistics<br>statistics-channels {<br> inet 192.168.20.2 port 8080 allow {<a href="http://192.168.10.0/24;" target="_blank">192.168.10.0/24;</a>};<br> inet 127.0.0.1 port 8083 allow { any; };<br>};<br><br># Logging module<br>include "/etc/opt/isc/scls/isc-bind/logging.conf";<br><br><br>#### Clients ACLs ####<br><br>acl deny-answer-referral-acl {<br> <a href="http://127.0.0.1/32" target="_blank">127.0.0.1/32</a>;<br> <a href="http://192.168.20.2/32" target="_blank">192.168.20.2/32</a>;<br>};<br><br>acl our-users-acl {<br> 127.0.0.1;<br> <a href="http://192.168.0.0/16" target="_blank">192.168.0.0/16</a>;<br>};<br><br>#### Users ####<br>view "our-users" {<br> match-clients { our-users-acl; };<br> allow-query { our-users-acl; };<br> recursion yes;<br> stale-answer-enable yes;<br> stale-cache-enable yes;<br> max-stale-ttl 12H;<br> stale-answer-ttl 30s;<br> stale-refresh-time 30s;<br> stale-answer-client-timeout 0;<br><br>zone "<a href="http://ourdomain.net" target="_blank">ourdomain.net</a>" {<br> type master;<br> file "zones/<a href="http://ourdomain.net" target="_blank">ourdomain.net</a>";<br> zone-statistics yes;<br> };<br><br>zone "." IN {<br> type hint;<br> file "named.root";<br> };<br>};<br><br>#### END OF NAMED CONFIGURATIONS<br><br></div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)"><br></div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)">Appreciate the support</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)"><br></div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)">Thank you</div><div style="font-family:tahoma,sans-serif;color:rgb(7,55,99)"><br></div><br></div>
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