Details of the event with ID 91 of the source Microsoft-Windows-CertificationAuthority

Event Source:	Microsoft-Windows-CertificationAuthority
Event ID:	91 (0x5B)
Event log:	Application
Event type:	Error
Symbolic Name:	MSG_E_DS_RETRY
Event text (English):	Could not connect to the Active Directory. Active Directory Certificate Services will retry when processing requires Active Directory access.
Event text (German):	Failed to connect to Active Directory. The process will be repeated as soon as access to Active Directory is required again during processing.

Example events

Could not connect to the Active Directory.  Active Directory Certificate Services will retry when processing requires Active Directory access.

Description

Occurs when the certificate authority cannot connect to a domain controller, for example, due to lack of network connectivity, firewall rules, or because all domain controllers are offline.

On the certification authority, the events are also 94, 44 and 9 logged.

Safety assessment

The security assessment is based on the three dimensions of confidentiality, integrity and availability.

The event may have an impact on the availability of the certification authority service. It should be alerted if not immediately followed by a Event with no. 77 is logged, which indicates that the connection has been restored.

Microsoft rating

Microsoft evaluates this event in the Securing Public Key Infrastructure (PKI) Whitepaper with a severity score of "Low".

Related links:

• Overview of Windows events generated by the certification authority
• Overview of audit events generated by the Certification Authority

External sources

• Event ID 91 - AD CS Active Directory Domain Services Connection (Microsoft)
• Securing Public Key Infrastructure (PKI) (Microsoft)