I just encountered queries on discourse.pi-hole.net and pi-hole-net from my Laptop. I didn’t had a browser open with any one URL, but just opened the pi-hole Frontend:
Is there a reason for those queries?
I’m unsure what you mean by “frontend”, but assuming you’re describing the login page, there is a link to discourse.pi-hole.net on there:
It sounds like your browser is performing DNS prefetching, ostensibly to speed up browsing. It is looking up any domains that it thinks that you might be likely to visit ahead of time so it is a few milliseconds faster when you click the link. There are of course privacy and security concerns with this practice, and Pi-hole’s login page specifically instructs browsers not to do this (code below, which you can verify by viewing the page source in your browser).
<!-- Usually browsers proactively perform domain name resolution on links that the user may choose to follow. We disable DNS prefetching here --> <meta http-equiv="x-dns-prefetch-control" content="off">
However, some browsers do not follow this directive. You can disable it manually in some of them, eg How to Disable Prefetch or Network Prediction in Google Chrome .
Thanks! indeed prefetch was activated. did not occur since deactivation