Sophos XG making a significant amount of DNS queries to www.google.com.*

Hi shred. Thank you for reaching out to Sophos community team. Based on the issue description I am suspecting the FQDN host has been present or already configured on XG for the above domains and if that is the case then XG self  DNS lookup generating those queries. 

Yep, they are the pre-configured FQDN hosts. I'm curious as to why there's so many DNS queries to some of them such as www.google.co.tz, www.google.com.tw, www.google.com.ar, etc. 240k+ queries in less than 24 hours on a single address seems like a lot.

I actually cleaned up the Safesearch enforcement  FQDN host group to only include the ones local to me. 

also be sure that there isn't a tcpdump or netstat running without the -n parameter. This is causing DNS requests for every packet.

See: https://community.sophos.com/sophos-xg-firewall/f/discussions/130821/constant-dns-lookups-to-google-domains-and-others-in-fqdn-hosts---fix/480777#480777