DNS

dig txt example.com @8.8.8.8
dig example.com | grep -v ";" | grep A
dig -x 8.9.10.11 | grep IN

sudo systemd-resolve --flush-caches

# flush DNS
systemctl restart nscd
 
# resolvconf
sudo systemctl enable resolvconf

dig @10.0.0.22 -p 8500 +short A www1.example.com