DOH firefox setting network.trr.mode=3


#1

I am using DNS over https and have firefox 63 setup as follows
-no proxy
-Operating DNS system set up with a fake non responsive DNS value
-The URL for DOH- https://mozilla.cloudflare-dns.com/dns-query

When I set Firefox to use network.trr.mode to a value of 3 which I understand to mean use only the DOH DNS values and do not fall back to any other, firefox fails to to resolve any sites. This worked prior to Dec-7-2018 but not anymore. Can you offer an explanation?


#2

3 does not seem to work for me either. Thats a question best for Mozilla.


#3

Mine works.

I have 63.0.3 on Mojave with trr.mode set to 3.

I also have trr.uri set to https://1.1.1.1/dns-query


#4

True, with the IP it does work.

And it makes sense after all, using a hostname for DNS resolution cant really work :+1:


#5

I have network.trr.uri set for https://mozilla.cloudflare-dns.com/dns-query which is the default for firefox. Does yours work using the default?


#6

Thanks. I have posted to mozila site https://support.mozilla.org/en-US/ as well. I thought this strange as it doesn’t allow evaluation of the network.trr.uri =https://mozilla.cloudflare-dns.com/dns-query alone as the other values will fall back to the OS DNS.

The firefox post is named DNS over https stops working"


#7

Surprisingly, yes, it does.

Mode is still 3, and the url is now the Mozilla one. I restarted Firefox and loaded up bbc.com then checked my about:networking screen for DNS and everything is still TRR=true.

And now we have a mystery. Granted, my Mac is set to use 1.1.1.1 for DNS, so that might have something to do with it.