Availability
The Availability entity is primarily the weighted result of the following availability-oriented checks
The result is also dependent on the total number of authoritative DNS servers serving the domain.
The availability entity is presented as a number between 0 and 100%. The trigger levels for each event is shown below. The lowest availability score (the highest severity) from all locations is displayed.
Note: The Availability score is assessed as the checks are executed. Some might argue that placing nameservers inside the same ASN (ASN residence) or even worse on the same subnet should affect the Availability score. We are aware of this but consider this as an infrastructural shortcoming that should be addressed by the client.
Event severities
INFO
90-100%
The domain is reachable and the DNS Servers are available. If the number is below 100% there might be issues of minor significance like minor timeout issues that doesn't have any major impact on the overall availability.
WARNING
60 - 90%
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.
ERROR
25 - 60%
Many of your customers experience problems reaching your sites. An Error severity usually means that half or more of the DNS infrastructure for the domain are unable to respond to queries or multiple DNS servers have serious timeout issues.
If this severity is present from multiple monitoring locations chance are that the problems exist on or in the vicinity of your DNS infrastructure.
CRITICAL
0 - 25%
The domain is virtually unreachable and your customers have serious problems accessing your sites.
Event messages
Messages can appear alone or in combination with each other.
{X} out of {Y} nameservers are unreachable.
Shows the number of name servers that are completely unreachable.
{X} out of {Y} nameservers have serious timeout issues.
Shows the number of name servers with serious timeout problems.
{X} out of {Y} nameservers have timeout issues.
Shows the number of name servers with timeout problems.
{X} out of {Y} nameservers don't accept TCP connections.
Shows the number of name servers that don't allow TCP queries.