Netlogon is a Windows service essential to trust relationships and several authentication operations in an Active Directory domain. When it fails, the diagnosis must take into account the secure channel, DNS, the discovery of domain controllers and the status of the service rather than a simple isolated network test.
Simple definition
A Windows service essential to trust relationships and authentication in a domain.
Technical definition
Netlogon maintains the secure channel between a computer and a domain controller and participates in the location and authentication of domain services.
What is it used for ?
Allow members and domain controllers to communicate in an authentic manner.
Practical example
A broken approval relationship may involve a secure channel problem managed by Netlogon.
What is the secure channel for? Netlogon ?
Netlogon participates in the trust relationship between a member machine and Active Directory and in several authentication operations. When a position reports a broken approval relationship, the problem may come from the secure computer account channel, but also from DNS, time or access to domain controllers.
Common issues
Test-ComputerSecureChannel -Verbose check the secure channel from PowerShell. nltest /sc_verify:DOMAINE provides additional control. Before any repair, check that the station uses the DNS Active Directory expected, that the time is correct and that a domain controller is reachable.
Diagnosis order Netlogon recommended
- Control DNS and discovery of the DCs.
- Check the time and connectivity.
- Test the secure channel.
- Reviewing Events Netlogon and authentication.
- Repair only after isolation of the secure channel as cause.
Related terms
Active Directory (AD) · Domain Controller · Kerberos
Key takeaway: This entry explains the general operation of the term. Exact settings may vary depending on software, vendors and environments.
FAQ — Netlogon
Should we get the machine out of the domain as soon as a relationship of trust fails?
No, check first. DNS, time, domain controller and secure channel; targeted repair may suffice.
What is Test-ComputerSecureChannel Test?
The command checks the secure channel relationship between the computer and the Active Directory domain.
Why? DNS Is it important for Netlogon ?
Active Directory machines use DNS to locate the domain services and controllers required for authentication.