services.doh-server.settings.ecs_allow_non_global_ip

By default, non global IP addresses are never forwarded to upstream servers. This is to prevent two things from happening:

1. the upstream server knowing your private LAN addresses;
2. the upstream server unable to provide geographically near results, or even fail to provide any result. However, if you are deploying a split tunnel corporation network environment, or for any other reason you want to inhibit this behavior and allow local (eg RFC1918) address to be forwarded, change the following option to "true".