Sentinel Identity
A detailed technical guide to buying a domain, understanding DNS, adding a custom domain to Microsoft Entra and Microsoft 365, and configuring DNS records such as MX, TXT, CNAME, SPF, DKIM, and DMARC.
A detailed technical guide to hybrid Microsoft sign-in architectures, including password hash synchronization, pass-through authentication, and federation with AD FS or PingFederate, with examples and backend validation flow.
A detailed technical guide to federation and token protocols, including SAML, WS-Federation, OAuth 2.0, and OpenID Connect, with examples, identity-provider roles, and backend flow analysis.
A detailed technical guide to core authentication methods, including Kerberos, NTLM, LDAP bind, passkeys, certificate-based authentication, and Windows Hello for Business, with examples and backend flow analysis.
A technical guide to the major authentication protocols and sign-in models used in Microsoft environments, including Kerberos, NTLM, LDAP bind, SAML, WS-Federation, OAuth 2.0, OpenID Connect, passkeys, certificate-based authentication, AD FS, and Microsoft Entra sign-in models.
A technical guide to Microsoft Entra Agent ID, including the agent identity model, Conditional Access enforcement, identity governance, risk detection, and network-level controls for AI agents.
A detailed technical guide to Microsoft Entra passkey sign-in, including relying-party behavior, same-device and cross-device flows, compatibility analysis, and rollout planning.
A detailed technical guide to Microsoft Entra passkey registration on Windows and mobile, including recent MFA requirements, Temporary Access Pass bootstrap, authenticator behavior, and policy evaluation.
A detailed technical guide to Microsoft Entra passkey policy, profile evaluation, AAGUID restrictions, attestation behavior, and rollout architecture.
A technical document for Microsoft Entra administrators covering how Microsoft Entra Backup and Recovery works, what it can recover, supported objects and properties, difference reports, recovery behavior, soft deletion, troubleshooting, and operational design guidance.
A detailed technical guide to AADSTS50020 in Microsoft Entra ID, including resource-tenant identity resolution, invitation redemption, cross-tenant access, and external identity design.
A detailed technical guide to Microsoft Entra join and registration failures on Windows, including device registration service flow, pending objects, dsregcmd analysis, and downstream impact on compliance and PRT.
A detailed technical guide to Microsoft Entra Primary Refresh Token failures on Windows, including dsregcmd analysis, device trust, broker behavior, network dependencies, and remediation design.
Technical troubleshooting for when Passkey (FIDO2) does not appear in Security info or Microsoft Authenticator, including Authentication Methods policy, MFA bootstrap, platform support, and authenticator constraints.
A detailed technical guide to why Microsoft Entra can block a sign-in from an Intune-compliant device, including device identity proof, browser support, client certificate behavior, and Conditional Access evaluation.
A detailed technical guide to browser behavior in device-based Conditional Access, including Edge, Chrome, Safari, private browsing, client certificate behavior, and support-matrix design.
A technical guide to Microsoft Entra passkeys for administrators, including passkey types, registration flows, Authentication Methods policy, Conditional Access, and deployment design.
A technical troubleshooting guide for Microsoft Entra passkeys covering registration failures, Conditional Access loops, Bluetooth issues, orphaned passkeys, compatibility gaps, and Authenticator-specific problems.
An engineering-level explanation of access tokens and refresh tokens in Microsoft Entra ID, including token ownership, lifetime, renewal, revocation, and common troubleshooting patterns.
A top-to-bottom engineering explanation of how Microsoft Entra Conditional Access evaluates scope, combines controls, and influences token issuance.
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About this site
Sentinel Identity publishes detailed Microsoft Entra, authentication, Conditional Access, DNS, and tenant security articles intended for administrators, architects, and cloud engineers who need implementation-level understanding.
Articles are written as technical reference material, with official Microsoft documentation linked inline where platform behavior, policy flow, and configuration details need to be validated.
Editorial standards
Long-form technical articles focused on Microsoft identity operations and architecture.
Official Microsoft sources linked throughout posts where product behavior needs validation.
Public privacy, terms, and cookie pages for transparency and reader trust.