Availability

The Availability metric is the combined and weighted result  from the individual availability checks run on each DNS server and provides an indicator of the overall availability of your DNS servers. Depending on the plan used for the domain in question the metric is calculated from the result of the checks below.

The result also depends on the total number of authoritative DNS servers serving the domain.

The availability entity is represented as a number between 0 and 100%. The trigger levels for each event are shown below. The lowest availability score (highest severity) from all locations is displayed on the dashboard.

Note!

The Availability score is assessed as the checks are executed. Arguably placing authoritative DNS servers inside the same AS and, even worse, placing them on the same subnet should affect the Availability score. We acknowledge this but have decided to leave these infrastructural shortcomings out of the overall score, although we urge that the client should consider addressing such issues.

The domain is reachable and the DNS Servers are available. If the number is below 100%, there may be minor problems such as minor timeout issues that don’t have a major impact on the overall uptime.

The DNS infrastructure experience disruptions that can affect the overall availability in a negative way. If the message or messages are persistent and/or frequent they need to be resolved. The message or messages inform about the extent of the problem. For Premium domain subscribers further details of the messages can be found in the drill-down matrix on the DNSmonitor dashboard.

Many of your customers are experiencing problems reaching your sites. An error severity usually means that half or more of the DNS infrastructure for the domain is unable to respond to queries, or that multiple DNS servers are experiencing severe timeout problems.

If this severity is present from multiple monitoring locations, there is a good chance that the problems are on or near your DNS infrastructure.

Event messages

Messages are compiled from the underlying checks. Please see the available messages under each check.