Ensuring that DNS is healthy and working as expected is fundamental to the performance and availability of any network service.

Kentik's DNS Server Monitor and DNS Server Grid tests already allow users to monitor and alert on the DNS Resolution Time - an important metric to track to ensure that no delays are introduced at this step of the interaction.

We've now enhanced these tests with the ability to monitor and alert on the IP mappings returned by the DNS servers being queried. By specifying an allowed list of IP addresses we can alert when an unexpected mapping is returned.

The Allowed DNS Results field under Advanced Options allows users to specify the expected IP results. If the test returns an IP that isn't in this allowed list the test health will be marked as Critical and an alert is triggered based on the alert activation settings.