DNS resolution method
The DNS resolution method does a DNS lookup (like nslookup using cmd). Only two queries are sent per test run that are trying to resolve the target hostname using the standard DNS server of a client. To respect caching only the response time of the second request is measured.
When to use the DNS resolution method
The DNS resolution method can be used to test the reachability of the standard DNS-Server and measures the response time. Due to caching only the second response is measured. The method exspects a valid response (e.g. no "Not found" response).
These are the parameters that are configurable for each test using the DNS resolution method.
Specifies the hostname of the target service.
The thresholds define the latency beyond which a measurement gets the status warning or critical. Your standard DNS server usually responds in up to 20ms. If a response takes more than 50ms it is gernally slow and might indicate a misconfigured DNS server. The name resolution query times out after 15s.
Base warning threshold:
Base critical threshold:
1 - 10.000 and the
warning threshold has to be less than the
Google name resolution test.
Limitations and recommondations
- The DNS queries are using port 53 UDP without authentication. This test does not use 53/TCP as Fallback or DNSSEC.