Why too many automatisms in DNS are bad (Pi-hole, FTL (dns.reply.host), mDNS/Avahi, etc.)

A small pre-face for users who followed the "Ultimate Pi-hole Setup" tutorial from the YouTuber WunderTech If you used the configuration files he provided on his homepage: https://www.wundertech.net/ultimate-pi-hole-setup/ you will experience the exact same problems sooner or later. The reason is that the VIPs from keepalived are not bound on a separate dummy interface and hence the pihole-FTL process will take them into account when dynamically building the hostname and choosing the "correct IPs". You HAVE to at least enable dns.reply.host in the /etc/pihole/pihole.toml to mark the static IP used for the server Pi-hole is running on. Jump to The solution if you are not interested in the details. Preface One of the main reasons why I have my homelab is to hone my skills. And today was a day this happened. From my one of my LAN hosts I wanted to connect to my Raspberry4 (raspi4.lan, IP: 192.168.178.8) via SSH. This host is configured as the secondary/backup instance in keepalived for…