Infrastructure is a dependency chain
Active Directory depends on DNS. Applications depend on services, networking, and name resolution. Hybrid identity depends on healthy on-premises infrastructure and clear cloud boundaries. This hub organizes those relationships so technicians can investigate the system behind the symptom.
Begin with the focused Test-KTDNS procedure, then use the domain-health guide when the symptom crosses DNS, discovery, replication, time, services, and connectivity.
Published investigation guide · Active Directory
Follow an evidence-first sequence from client scope through locator records, domain-controller checks, replication, time, services, and logs.
Open the domain-health guidePublished tutorial · DNS
Download, verify, review, and run the DNS-only tool, then interpret its normalized results without overstating what one query proves.
Open the Test-KTDNS tutorialVersioned download
Download the release with its source, README, tests, license, and checksum manifest from one versioned location.
Open DownloadsLearning method
Use the MSP University sequence to understand dependencies, collect evidence, isolate the cause, and verify the result.
Review the learning pathThe published DNS tool is linked directly. Other lanes establish where future reviewed learning will belong without inventing tutorials or cases.
Published investigation guide
Investigate client configuration, domain discovery, member secure channels, controller advertising, services, replication, time, and logs.
Investigate domain healthPublished tool available
Name resolution, record types, resolver selection, response evidence, and the DNS dependencies that affect domains, services, and applications.
Use the read-only DNS toolContent in development
Scopes, leases, options, reservations, relay paths, and the client configuration that connects addressing to DNS and routing.
Content in development
Roles, features, dependencies, update state, storage, scheduled work, and practical server administration evidence.
Published investigation guide
Review replication, SYSVOL and NETLOGON evidence, time, domain-controller reachability, and signals that distinguish local from domain-wide failures.
Use the evidence-first guideContent in development
Service state, dependencies, startup behavior, recovery, accounts, and the difference between a stopped service and an underlying failure.
Content in development
Time-bounded evidence, provider context, event correlation, useful filters, and ways to avoid treating isolated warnings as root cause.
Content in development
Addressing, routes, ports, firewall boundaries, name resolution, path testing, and the evidence that separates reachability from application health.
Content in development
On-premises identity health, synchronization boundaries, DNS, time, authentication, and the dependencies that surface in Microsoft cloud services.
One public tool
Read-only discovery and stable output begin with Test-KTDNS. Other Windows, server, and Active Directory tools remain private or in development.
Explore the PowerShell LibraryTwo published guides now connect focused DNS testing with a broader Active Directory and domain-health investigation. Additional Windows and hybrid procedures remain in development.
Published tutorial · DNS
Verify the release, query a selected resolver and record type, read the stable output, and use the result as one piece of troubleshooting evidence.
Use the Test-KTDNS procedurePublished investigation guide · Active Directory
Determine which dependency is associated with the symptom before planning an environment-specific repair.
Open the domain-health investigationCurrent tutorial catalog
The tutorial catalog now includes this Windows/DNS procedure alongside the published Microsoft 365 and Exchange Online guidance.
View all current tutorialsContent in development
Future procedures will cover other Windows Server, service, event-log, networking, and hybrid scenarios only after technical review.
The first public release is narrow by design: read-only DNS troubleshooting with source, tests, documentation, and checksums.
PowerShell · v1.0.0
Review supported record types, requirements, stable output, terminating errors, checksum verification, and the Authenticode limitation.
Review release detailsPackage integrity
Get the ZIP and checksum manifest from the Downloads page before reviewing or running the script.
Open the download packageFuture tools
Additional Active Directory, server, service, event-log, networking, and hybrid tools will appear only after review, testing, documentation, and packaging.
No Windows or hybrid case is published yet. This lane is reserved for sanitized investigations that preserve useful infrastructure reasoning.
Windows & Hybrid cases
Future cases may cover directory health, DNS, services, event evidence, connectivity, replication, and hybrid dependencies after privacy and technical review.
Current case catalog
The current case library contains two anonymized Microsoft 365 investigations and does not claim a Windows case.
Browse current casesCase method
Published cases separate confirmed findings, hypotheses, remediation, and verification instead of presenting a symptom as a root cause.
Review the case flow