Updated at: June 10, 2023
Under TUN Mode, the system will choose to use the System DNS configured in the Brook or Shiliew client.
There are no issues, no action required.
However, under App Mode, up to now, Apple will choose to use the DNS configured in the system settings. This could cause a minor issue, as described below.
Go to System Settings - WiFi - Details - DNS - Obtain automatically
By default, if you see two DNS servers assigned automatically (in gray): one IPv4, such as 192.168.1.1, and one IPv6, such as fe80::1
Then open the terminal, execute dig http3.ooo
multiple times
If you see GUA, there is no problem.
Set the DNS in System Settings - WiFi - Details - DNS - to 8.8.8.8