Feature Description

For now, DNS returns SERVFAIL if datacenter is not available or if it does not exists. We would like to propose to return NXDOMAIN (RCODE: 3) when datacenter does not exist and keep SERVFAIL if DC exists and cannot be reached.

Use Case(s)

The DNS servers caching queries might use this information to keep track of queries constantly failing and have different behavior for those errors.

Implementation

This information might be already available since we know can find if the DC does exists or not: https://github.com/hashicorp/consul/blob/master/agent/consul/rpc.go#L607 since be50400 has been merged.

So, DNS server would only have to check for:

• ErrDCNotAvailable and return SERVFAIL (current case)
• ErrNoDCPath return NXDOMAIN