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Version: 2.2.1-preview

AD-DNS-05 - Dynamic DNS record count should be retrievable

Michael SouleMerill Fernando
Contributed by Michael Soule with Merill FernandoAll contributors →

Overview​

Dynamic DNS allows clients to register and update their own DNS records. While convenient, excessive dynamic registration can indicate:

  • Security risks: Unauthorized devices may register in DNS
  • Configuration issues: Misconfigured clients may create excessive records
  • Stale data: Dynamic records may not be cleaned up properly
  • Resource exhaustion: Too many dynamic records can impact DNS performance

Understanding the ratio of dynamic to static records helps assess the security and hygiene of your DNS environment.

Security Recommendation​

  • Enable secure dynamic updates only (require authentication)
  • Implement aging and scavenging to remove stale records
  • Monitor for unusual patterns in dynamic registration
  • Restrict dynamic updates to authorized systems only

How the Test Works​

This test counts DNS records that have timestamps (dynamic) versus those without (static) and reports the ratio.

  • Test-MtAdDnsZoneRecordDetails - Provides detailed record counts per zone

Test Metadata​

FieldValue
Test IDAD-DNS-05
SeverityInfo
SuiteActive Directory
CategoryAD.DNS
PowerShell testTest-MtAdDnsDynamicRecordCount
TagsAD, AD-DNS-05, AD.DNS

Source​

  • Pester test: tests/ad/dns/Test-MtAdDnsDynamicRecordCount.Tests.ps1
  • PowerShell source: powershell/public/ad/dns/Test-MtAdDnsDynamicRecordCount.ps1