Как исправить ошибку «Сервер LDAPS на порту 636 недоступен» и ошибки недоверенного сертификата

Are your firewalls, backup solutions, or 3rd-party applications suddenly failing to authenticate against Active Directory with LDAP Error 0x51 or "Server Not Reachable" on port 636? In this comprehensive sysadmin guide, we break down why LDAPS fails, how to troubleshoot port 636 and untrusted certificate errors, and how to properly configure SSL/TLS certificates on your Domain Controllers without compromising security. Watch the full video here: https://www.youtube.com/watch?v=8CDTNY2R1WY ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 📌 TIMESTAMPS / CHAPTERS ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ [00:00:00] - Introduction: The Dreaded LDAPS Lockout [00:01:22] - Section 1: The Port 636 Problem & LDAP Signing Requirements [00:02:38] - Section 2: Diagnosing the Root Cause (ldp.exe, Certutil, OpenSSL, PowerShell) [00:03:52] - Section 3: Anatomy of a Valid LDAPS Certificate (The 5 Prerequisites) [00:05:40] - Section 4: Resolving the Error (Enterprise CA vs. PowerShell Self-Signed Certs) [00:07:22] - Section 5: Restoring Client Connectivity (Firewalls, Java cacerts & Veeam) [00:08:49] - Pro Tip: Certificate Lifecycle Management ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔑 WHAT YOU WILL LEARN ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✔ Why Microsoft enforces LDAP signing and pushes traffic to LDAPS (Port 636) ✔ How to test LDAPS bindings properly using ldp.exe, certutil, and OpenSSL ✔ The 5 critical certificate requirements (Server Auth EKU 1.3.6.1.5.7.3.1, SAN matching FQDN, Schannel provider, etc.) ✔ Pro Tip: Using the NTDS Certificate Store for automatic binding without restarting DCs ✔ How to request certificates via Active Directory Enrollment Policy (Domain Controller template) ✔ How to generate a working self-signed certificate using PowerShell (`New-SelfSignedCertificate`) ✔ Fixing client trust issues on SonicWall firewalls, Java truststores (`cacerts`/`keytool`), and Veeam ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 💡 KEY COMMANDS & TOOLS ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ • Diagnostic Tools: `ldp.exe`, `certutil`, `openssl s_client`, `Test-NetConnection` • Management Console: `certlm.msc` (Local Machine Certificates) • Store Location: NTDS Service Certificate Store ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 🔔 SUBSCRIBE & CONNECT ━━━━━━━━━━━━━━━━━━━━━━━━━━━━ If this guide saved your Monday morning, don't forget to like, subscribe, and hit the notification bell for more sysadmin, Active Directory, and infrastructure deep dives! #ActiveDirectory #LDAPS #SysAdmin #WindowsServer #CyberSecurity #Port636 #Networking #ITSupport