DNS Errors

Description

An application or server had an unusual increase in DNS errors, which indicates that domain name lookups failed. Services might be unable to resolve hostnames.

Background

The DNS protocol translates human-readable hostnames into IP addresses, which is necessary for network communication. A spike in DNS errors such as NXDOMAIN, SERVFAIL, or REFUSED indicates failures to resolve hostnames. This issue might be related to misconfigured client applications that attempted to reach incorrect hostnames, unavailable DNS servers, or unauthorized hostname scans.

Mitigation Options

Monitor DNS server health by checking DNS server logs for high resource utilization or service crashes.

Verify that client devices are pointing to the correct DNS servers.

Check for misconfigurations such as incorrect search suffixes or outdated hostnames.

Inspect firewalls to ensure that port 53 is not throttled or blocked.

Verify that there are no resource bottlenecks in the network path to the DNS server.

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