Quad9 utilizes multiple network providers in our global network. When running a DNS leak test, or determining the IP address which is used to perform the recursive DNS query using a test like:
dig +short A whoami.akamai.net
it's expected to see IP addresses owned by the following providers:
- WoodyNet (AKA PCH.net)
- GSL Networks
These organizations are also listed on the Sponsors page of the Quad9 website: https://quad9.net/about/sponsors
If you are trying to simply determine if you are using Quad9, you can visit https://on.quad9.net instead of relying on a DNS leak test. However, a DNS leak test can be useful to ensure you're exclusively using Quad9, which is required to ensure that all of your DNS requests will be protected by Quad9.