All possible errors
Because DNS is a relatively simple protocol, it’s possible to list every error that could occur.
Operation timed out
dog did not receive a response to the request it sent within the allowed duration.
dog received a response to the request indicating that the port is closed or inaccessible.
The certificate was not trusted
When using the TLS or HTTPS transport types, the certificate presented by the server was not trusted. This could mean it has expired, it’s for the wrong host, it’s self-signed, or one of the many other reasons this could happen.
The HTTPS nameserver responded with a Bad Request status code.
Record overflow or handshake failure
There was an error in one of the TLS or HTTPS response packets.
Transaction ID mismatch
We received a response but the first two bytes weren’t correct.
The DNS data in the response did not conform to the DNS specification.