This monitor verifies that the domain member can bind to the LDAP and GC port of all domain controllers in a domain.
If the DC does not respond to ping or is not advertising it will ignore it and rely on other monitors to determine if that is an issue.
If the DC is advertising it will bind to the LDAP port and if the DC is GC it will bind to the GC port. If a bind fails on any DC the monitor will raise an alert.
Possible causes of failures include the following:
The Netlogon Service is not running.
The hard drives on the Domain Controller (DC) may be full, inspect free space on the DC.
The Domain Controller is not healthy and may need to be replaced.
Ensure that the failing Domain Controller(s) are online and functioning correctly.