we are running an icinga2 cluster with >1.5k hosts monitored. I was tracing down a different issue with our dns when I found out that icinga2 resolves the PTR record to every IP address it gets. This ends in thousands of SERVFAILS per minute.
When there is a hostname in “address” it resolves A first, then AAAA and then PTR to the A record. When there is an IP it only resolved PTR.
Is this a feature or a bug?
# icinga2 --version icinga2 - The Icinga 2 network monitoring daemon (version: r2.11.3-1) Copyright (c) 2012-2021 Icinga GmbH (https://icinga.com/) License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl2.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. System information: Platform: Debian GNU/Linux Platform version: 9 (stretch) Kernel: Linux Kernel version: 4.9.0-12-amd64 Architecture: x86_64 Build information: Compiler: GNU 6.3.0 Build host: runner-LTrJQZ9N-project-298-concurrent-0 Application information: General paths: Config directory: /etc/icinga2 Data directory: /var/lib/icinga2 Log directory: /var/log/icinga2 Cache directory: /var/cache/icinga2 Spool directory: /var/spool/icinga2 Run directory: /run/icinga2 Old paths (deprecated): Installation root: /usr Sysconf directory: /etc Run directory (base): /run Local state directory: /var Internal paths: Package data directory: /usr/share/icinga2 State path: /var/lib/icinga2/icinga2.state Modified attributes path: /var/lib/icinga2/modified-attributes.conf Objects path: /var/cache/icinga2/icinga2.debug Vars path: /var/cache/icinga2/icinga2.vars PID path: /run/icinga2/icinga2.pid
# icinga2 feature list **Disabled features:** compatlog debuglog elasticsearch gelf graphite icingastatus influxdb livestatus opentsdb perfdata statusdata **Enabled features:** api checker command ido-mysql mainlog notification syslog