I have turned on this DoH (DNS over HTTPS) thing in Firefox for the last several weeks. It is a method of encrypting DNS request (eg determining where web servers are) so they can’t (or approximately) be read or modified by third parties. I am using both CloudFlare’s (the default) and Quad9’s servers.

Enabling is as simple as:

  1. Go to the general preferences pane
  2. Go to the “Network Settings” section near the bottom and press the “Settings” button
  3. Check “Enable DNS Over HTTPS”
  4. See below that to change the DNS server, if desired

However, this is supposed to become enabled by default tomorrow, so this may be irrelevant.

I haven’t noticed any problems, or any differences at all really.

I’ve seen a strangely large number of complaints about the system, but they seem mostly unimportant, disingenuous, or more of informative of the situation than complaints. There are few DoH servers now, but that will improve over time if the system is adopted, and eliminate funneling traffic through one or a few providers. IP’s of requested websites can still be seen by observers, just like without DoH. VPN’s can be used to encrypt those and DNS at the same time. Corporate and other security Men in the Middle can have more trouble controlling traffic, but they can still see IP’s of requests, unless that VPN option is used, in which case DNS requests are encrypted anyway.

It seems like a step in the right direction to me.