# Entra Domain Services LDAPS certificate renewal for Atlas clients > Source-anchored research for Entra Domain Services LDAPS certificate renewal for Atlas clients. Run status: COMPLETED. Parent: [Atlas LDAP Azure AD DS](https://llms-explorer.com/tree/atlas-ldap-azure-ad-ds/) · 4 facets · 8 facts · page: https://llms-explorer.com/tree/entra-domain-services-ldaps-certificate-renewal-for-atlas-clients/ ## Structure and components - Recommended renewal coordination, inferred from the two vendor guides: determine whether Atlas already trusts the replacement issuer and, if additional trust is required, update the LDAP CA Root Certificate field as part of the managed-domain certificate change. Atlas accepts comma-separated CA certificates and self-signed certificates, while Microsoft requires LDAP clients to trust the issuer. These facts support planning trust overlap but do not specify an atomic cross-service update sequence or establish a tested Atlas zero-downtime rotation procedure. (medium confidence) — [source](https://learn.microsoft.com/en-us/entra/identity/domain-services/tutorial-configure-ldaps) · [also](https://www.mongodb.com/docs/atlas/security-ldaps-azure.md) ## How it works - Microsoft states that secure LDAP access to a managed domain is disrupted when its certificate expires. Combined with NocTel’s advice to set a renewal reminder and check the Azure portal expiration date, this supports tracking the LDAPS certificate expiry before a renewal becomes an authentication incident. (medium confidence) — [source](https://learn.microsoft.com/en-us/entra/identity/domain-services/tutorial-configure-ldaps) · [also](https://warden.noctel.com/docs/azure-ad.html) - As an operator-selected monitoring pattern, OpenSSL 3.5 can inspect the current LDAPS certificate file with `openssl x509 -in ldaps.pem -noout -enddate` and test a 30-day renewal threshold with `openssl x509 -in ldaps.pem -noout -checkend 2592000`. The documented -checkend result is nonzero when the certificate expires within the specified seconds and zero otherwise; this file check does not itself establish that the endpoint is serving that certificate. (low confidence) — [source](https://docs.openssl.org/3.5/man1/openssl-x509/) ## Problems, failure modes and limitations - If TLS fails after replacement, check expiry, hostname matching and issuer trust separately. Microsoft describes the client’s name and issuer validation during the TLS handshake; NocTel’s managed-domain integration guide lists expiration, hostname mismatch and missing trust as separate certificate-error checks. (medium confidence) — [source](https://learn.microsoft.com/en-us/entra/identity/domain-services/tutorial-configure-ldaps) · [also](https://warden.noctel.com/docs/azure-ad.html) ## Facts and statements - In the Microsoft source retrieved on 2026-10-31, Microsoft’s documented renewal procedure is to create a replacement secure LDAP certificate, apply it through Microsoft Entra Domain Services > Secure LDAP > Change Certificate in the Entra admin center, and distribute the certificate to clients that connect using secure LDAP. (medium confidence) (verified as of 2026-10-31) — [source](https://learn.microsoft.com/en-us/entra/identity/domain-services/tutorial-configure-ldaps) · [also](https://learn.microsoft.com/en-us/entra/identity/domain-services/alert-ldaps) - Recommended renewal validation, inferred from Microsoft replacement instructions and Atlas configuration checks: after replacing the managed-domain certificate and making any necessary Atlas trust changes, use Atlas Verify and Save and wait for deployment. Atlas documents checking that clusters can connect to, authenticate with and query the LDAP server; a successful certificate upload alone does not perform those Atlas-side checks. (medium confidence) — [source](https://learn.microsoft.com/en-us/entra/identity/domain-services/alert-ldaps) · [also](https://www.mongodb.com/docs/atlas/security-ldaps-azure.md) - A February 23, 2024 first-person Microsoft Q&A report describes an expiring LDAPS certificate whose previous administrator’s certificate could not be located; the questioner subsequently reported successfully creating a new certificate. This is historical evidence of a renewal handoff problem, with no demonstrated Atlas outage or downtime result. (low confidence) — [source](https://learn.microsoft.com/en-us/answers/questions/1572809/how-to-renew-secure-ldap-cert-for-microsoft-entra) - In the Microsoft source retrieved on 2026-10-31, Microsoft documents AADDS502 as the managed-domain secure-LDAP certificate-expiry alert; its message includes the expiration date. The documented resolution requires both applying a replacement certificate to Domain Services and distributing it to LDAP clients. (low confidence) (verified as of 2026-10-31) — [source](https://learn.microsoft.com/en-us/entra/identity/domain-services/alert-ldaps)