Frequently Asked Questions (FAQ)
10. Why do I receive "unknown host xxx" error when I can still access my website/server?
This error occurs when our system is unable to resolve your domain name, and this indicates a problem with your DNS servers. This can happen due to all of your DNS servers being down, or connectivity to the DNS servers was down.
You may not notice DNS problems immediately if you use cached DNS records rather than make new DNS queries. This is often the case if you access the website/server regularly and have the DNS records in cache. However, your visitors (especially first time visitors) will not be able to resolve the domain.
Our system is configured to perform a new DNS query on each check so that we can catch DNS problems instantly. Due to the caching behaviour described above, you may regard the reported error as false. This is not the case as the error is confirmed from multiple monitoring locations.
You can also bypass DNS checking by monitoring with the website/server IP address instead of domain name. If you choose to do this, please make sure you monitor your DNS servers separately.