Issue with dns DoH firefox and Openvpn

blackexpresso

Hello guys,

I'm French, i will try to explain what is the issue.

I use a vpn. i use too dnscrypt for normal dns queries.

In the vpn, we all have dns servers servicies.

But, firefox allow user to enable TRR (Doh) and set an ip and an https adress.

So for example, i can use

9.9.9.9
https://dns.quad9.net/dns-query

But, when i use openvpn and my vpn.

There is an option to prevent dns leak.

block outside dns.

But after some tests with TRR mode in firefox, there is an issue.

When i go to dnsleaktest.com vpn connected. first page, it show the vpn node ip.

But if i do an extended test, the only server found is the firefox Doh server....

Normal way, it's impossible.

So the block outside dns is not working in this case....

https://cjoint.com/c/HLtwUdoa2w6

Thanks

Regards