C-Ares cannot find DNS Servers

[robert.d...@gmail.com]

The gRPC client is unable to resolve DNS address of the server unless the GRPC_DNS_RESOLVER environment variable to "native". I expected gRPC to work out of the box and c-ares would be able to resolve the servers DNS address.

Below are the logs:

I0814 18:33:56.089860 0 T:\src\github\grpc\workspace_csharp_ext_windows_x64\src\core\ext\filters\client_channel\resolving_lb_policy.cc:318: resolving_lb=000002315BE67890: resolver transient failure: {"created":"@1565822036.090000000","description":"DNS resolution failed","file":"T:\src\github\grpc\workspace_csharp_ext_windows_x64\src\core\ext\filters\client_channel\resolver\dns\c_ares\dns_resolver_ares.cc","file_line":358,"grpc_status":14,"referenced_errors":[{"created":"@1565822036.088000000","description":"C-ares status is not ARES_SUCCESS: Could not contact DNS servers","file":"T:\src\github\grpc\workspace_csharp_ext_windows_x64\src\core\ext\filters\client_channel\resolver\dns\c_ares\grpc_ares_wrapper.cc","file_line":244,"referenced_errors":[{"created":"@1565822036.088000000","description":"C-ares status is not ARES_SUCCESS: Could not contact DNS servers","file":"T:\src\github\grpc\workspace_csharp_ext_windows_x64\src\core\ext\filters\client_channel\resolver\dns\c_ares\grpc_ares_wrapper.cc","file_line":244}]}]}

### What version of gRPC and what language are you using?

 C# .Net Standard 2.0

 gRPC 1.21.0

Any help is greatly appreciated!