Secondary DNS Minor Updates: auto-enable and NOTAUTH

We’ve made a couple minor updates to the Secondary DNS system.

  • If we see a successful transfer, the back end will automatically send an “enable” flag to the account control center. This addresses a possible condition where a zone can become disabled between update runs due to an error that was fixed before the next run.
  • Secondary DNS zones will be automatically disabled if a NOTAUTH (not authoritative) response is received from the configured master. This is similar to the existing behavior of disabling on a REFUSED response. Our system must assume that if the master is not authoritative for a zone that we must not try to be a secondary, and it wastes resources to keep trying.