We were unable to connect to any of your name servers in a timely manner. This is a critical error.
Your website, email, and other critical services tied to your domain are likely down. Users may not be able to access your website or send you email.
Typos in your DNS or a spelling error in your domain name could be causing this issue.
If none of your name servers are responding to queries, then it will be impossible for anyone to resolve any of your records. It also means that anyone without cached DNS data will be unable to connect to any of your servers or services. Monitoring your name servers with a third party is critical because you will most likely have cached of your own domain information and it is likely that you will not immediately feel the effects of the failure of your name servers.
For many reasons we highly recommend that you configure at least a second notification email address that is not part of the domain you are monitoring. If your name servers are offline, then your MX records will be unavailable and it is likely that notification messages would fail to be delivered.
Another common scenario when you might find all of your name servers offline is during DNS migrations. If you fail to update your NS records with your registar or fail to update the NS records in the zone, then you could find that your zone is referencing either servers that have been shut down, have had your zone removed, or have been set as not Authoritative.