Enabling debug logging for the Netlogon service

Activate debug logging using nltest and set log size using registry

Type the following command, and then press Enter to enable logging:

Nltest /DBFlag:2080FFFF

 

Setting the maximum log file size for Netlogon logs using Registry

The MaximumLogFileSize registry entry can be used to specify the maximum size. You must create this entry, because it doesn´t exist.

Path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters

Value Name: MaximumLogFileSize

Value Type: REG_DWORD

Value Data: <max log file size in bytes>

1073741824 Bytes is 1 GB

This registry setting specify the disk space for the Netlogon.log and Netlogon.bak file. For example, a setting of 1 GB can require 2 GB of disk space.

Using Policy to enable logging and configuring log size

You can use the following Computer policy to configure the log file size in bytes and debug level:

Computer Configuration\Administrative Templates\System\Net Logon\Specify maximum log file size

1073741824  (1073741824 is 1 GB)

Computer Configuration\Administrative Templates\System\Net Logon\Specify log file debug output level

545325055     (545325055 is equivalent to 0x2080FFFF and enables verbose Netlogon logging!)