Re: BIND 9.18.48 Crash upon Serve Stale Enabling, with general: critical: exiting (due to assertion failure) and Recursion Loop Detected

You are running outdated version - BIND 9.18.41, first step would be to upgrade to latest 9.18 version or even better to latest 9.20 as BIND 9.18 will reach end of life quite soon.

Ondrej

--
Ondřej Surý (He/Him)
[email protected]

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!

My working hours and your working hours may be different. Please do not feel obligated to reply outside your normal working hours.

On 3. 5. 2026, at 9:40, Ibrahim Almahfooz <[email protected]> wrote:



Hi,

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:

*Sample from named.run logs showing the recursion loop:

03-May-2026 07:37:41.553 client: info: client @0x7f32d0d4c498 10.40.153.193#14013 (api.al-array.com ): view our-users: recursion loop detected
03-May-2026 07:37:41.553 client: info: client @0x7f32d0993c98 10.36.16.177#10683 (api.al-array.com ): view our-users: recursion loop detected
03-May-2026 07:37:41.702 client: info: client @0x7f32d0da7098 10.36.24.213#47838 (ninja12002.serv00.net ): view our-users: recursion loop detected
03-May-2026 07:37:41.717 client: info: client @0x7f32d25e4098 10.48.72.221#37292 (hayward.walsivrtgam.net ): view our-users: recursion loop detected

*Sample from default logs showing the assertion failure:

default.1:03-May-2026 07:38:30.213 general: critical: /opt/isc/isc-bind/root/usr/lib64/libisc-9.18.41.so (isc_assertion_failed+0xe) [0x7f32d615538e]
default.1:03-May-2026 07:38:30.213 general: critical: exiting (due to assertion failure)

*Our resolver is receiving around 20k QPS.

*Below is the configuration
## Global Named Configuration
options {
directory "/var/opt/isc/scls/isc-bind/named/data";
listen-on { 127.0.0.1; 192.168.20.2; };
allow-transfer {"none";};
dnssec-validation auto;
querylog no;
recursive-clients 10000;
dnstap {all;};
dnstap-output file "named-logs/dnstap.file";
dnstap-identity "ns02.ourdomain.net ";
deny-answer-addresses { deny-answer-referral-acl; };
};

# For monitoring systems to fetch named statistics
statistics-channels {
inet 192.168.20.2 port 8080 allow {192.168.10.0/24; };
inet 127.0.0.1 port 8083 allow { any; };
};

# Logging module
include "/etc/opt/isc/scls/isc-bind/logging.conf";

#### Clients ACLs ####

acl deny-answer-referral-acl {
127.0.0.1/32 ;
192.168.20.2/32 ;
};

acl our-users-acl {
127.0.0.1;
192.168.0.0/16 ;
};

#### Users ####
view "our-users" {
match-clients { our-users-acl; };
allow-query { our-users-acl; };
recursion yes;
stale-answer-enable yes;
stale-cache-enable yes;
max-stale-ttl 12H;
stale-answer-ttl 30s;
stale-refresh-time 30s;
stale-answer-client-timeout 0;

zone "ourdomain.net " {
type master;
file "zones/ourdomain.net ";
zone-statistics yes;
};

zone "." IN {
type hint;
file "named.root";
};
};

#### END OF NAMED CONFIGURATIONS

Appreciate the support

Thank you

--
Visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list.

-- 
Visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list.