Non-RFC1918 (public IP) subnets details should be retrievable

Contributed by Michael SouleAll contributors →

Part of Active Directory · Active Directory · Sites and subnets · All checks

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Invoke-Maester -TestId AD-SUB-07

Overview

Detailed information about public IP subnet usage helps:

• Identify misconfigurations: Find subnets that should use private ranges
• Assess security posture: Evaluate exposure of internal resources
• Plan remediation: Prioritize subnet renumbering efforts
• Document exceptions: Record legitimate uses of public IPs

Each public IP subnet should be reviewed for proper isolation and business justification.

Control Type

Detective

Security Recommendation

For each public IP subnet:

1. Verify if the use is intentional and justified
2. Ensure proper network isolation is in place
3. Document the business requirement
4. Plan migration to private ranges if appropriate
5. Review firewall and NAT configurations

How the Test Works

This test retrieves all subnets, identifies those using public IP ranges, and lists them with their site associations and descriptions.

Related Tests

• Test-MtAdSubnetNonInternalCount - Counts public IP subnets
• Test-MtAdSubnetTotalCount - Counts total subnets
• Test-MtAdSubnetSiteAssociationCount - Counts sites with subnets

Details

Every attribute of this check

Field	Value
Test ID	AD-SUB-07
Severity	Info
Suite	Active Directory
Product	Active Directory
Feature	Sites and subnets
Area	Infrastructure hardening
Resource type	AdSite
MITRE ATT&CK	None
PowerShell test	Test-MtAdSubnetNonInternalDetails
Services	ActiveDirectory
Permissions	ActiveDirectory:Ldap:subnet:ReadProperty

Source

• Test: tests/ad/site/Test.AD-SUB-07.ps1
• Documentation: tests/ad/site/Test.AD-SUB-07.md