Zone Health
Run a health check on any DNS zone to verify nameservers, mail records and security policies are in order.
| Check | Status | Records |
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About the Zone Health checker
A domain's DNS zone is the complete set of records that define how it behaves, and a healthy zone needs more than just correct individual records, it needs properly configured name servers, consistent responses across all of them, and no single point of failure. This tool checks the overall health of a domain's zone, looking at name server configuration, response consistency, and resilience, giving you a broader picture than checking individual record types alone.
How it works
DNSbyte queries all of a domain's authoritative name servers directly and compares their responses for consistency, since all name servers for a domain should return identical answers. It also checks for redundancy, whether the domain has multiple name servers hosted in genuinely separate infrastructure rather than all behind a single provider, which matters for resilience if one provider has an outage.
Results cover name server count and consistency, whether SOA (Start of Authority) values match across all name servers, and whether the zone shows signs of being properly redundant.
Frequently asked questions
Why do I need more than one name server?
A single name server is a single point of failure, if it becomes unreachable, your entire domain stops resolving for anyone whose resolver has not cached your records. Most registries require at least two name servers for exactly this reason, and many providers recommend more for additional resilience.
What does it mean if my name servers return inconsistent answers?
This typically indicates a zone transfer problem, where changes made on a primary name server have not yet propagated to a secondary, or a misconfiguration where the name servers are not actually serving the same zone data. This can cause unpredictable behaviour depending on which name server a resolver happens to query.
What is SOA and why does it matter for zone health?
The Start of Authority record contains key metadata about the zone, including a serial number that should increment every time the zone changes. If name servers show different serial numbers, it usually means they are out of sync with each other.
Is it bad if all my name servers are with the same provider?
It introduces a single point of failure at the infrastructure level, if that one provider has an outage, all of your name servers become unreachable simultaneously even though there are multiple of them. Using name servers from two different providers, sometimes called secondary DNS, provides genuine redundancy.
How often should I check my zone health?
There is no need to check routinely if nothing has changed, but it is worth checking after any change to name servers, after switching DNS providers, or if you are troubleshooting intermittent resolution issues that do not show up in a simple single lookup.