Active Directory Domain Services (AD DS) 2025

Article No :: 33

Active Directory Domain Services (AD DS) 2025

🛠️Active Directory Domain Services (AD DS) 2025: Game-Changing Features Every Sysadmin Needs to Know

Welcome to the future of identity management! Microsoft has rolled out Windows Server 2025, and it brings massive upgrades to Active Directory Domain Services (AD DS) 2025. From deeper security hardening to smarter replication control, this version is built to handle modern enterprise demands. If you're a sysadmin maintaining complex infrastructures, here's everything you need to watch out for.

🧩 Hardware Requirements

Component	Minimum Requirement
Processor	64-bit, 1.4 GHz or faster, x64 architecture
RAM	2 GB (Server Core); 4 GB+ recommended
Storage	32 GB minimum; 64 GB+ recommended
Network	Gigabit Ethernet adapter (PCI Express)
Firmware	UEFI 2.3.1c with Secure Boot
TPM	TPM 2.0 (for security features like BitLocker)
Graphics	Super VGA (1024 x 768) or higher resolution

🧠 Tip: ECC memory is recommended for domain controllers to ensure reliability.

🛠️ Software & Configuration Requirements

• Operating System: Windows Server 2025 (Standard or Datacenter edition)

• Functional Level:

  • Minimum forest and domain functional level: Windows Server 2016

  • Required to enable features like 32K database pages and schema upgrades

  • Roles & Features:

    • AD DS role must be installed via Server Manager or PowerShell

    • DNS Server role is recommended for integrated name resolution

  • Static IP Address: Required for domain controller stability

  • Administrator Privileges: Needed to promote the server to a domain controller

🔐 Security Requirements

• TLS 1.3 support for LDAP over TLS

• LDAP Sealing is enabled by default

• Kerberos Enhancements: AES SHA-256/384 support

• SAM-RPC Hardening: Legacy password methods deprecated

🔄 Functional Level 10: The New Standard

• Enables 32K database pages and advanced schema features.

• Requires domains to be at least on Windows Server 2016 functional level.

• Backwards compatible, but upgrading unlocks full potential.

🧩 Sysadmin Tip: Upgrade your forest functional level before promoting Server 2025 DCs.

🧮 Jet Blue Database Upgrade

• Page size increased to 32K (from 8K).

• Benefits:

  • Objects up to 32KB.

  • Multi-value attributes: up to 3200 entries.

  • Reduced fragmentation, faster I/O.

💡 Why It Matters: Smoother replication and backup operations.

🔐 Security That’s Actually Secure

• TLS 1.3 for LDAP: Stronger encryption by default.

• LDAP Sealing Enabled: Confidentiality after SASL binds.

• Kerberos Enhancements:

  • AES SHA-256/384 support.

  • Improved PKINIT agility.

• SAM-RPC Hardening: Legacy password methods deprecated.

🧱 Bonus: Machine account passwords are now randomised to prevent brute-force attacks.

🧠 True NUMA Support

• AD DS now utilises NUMA architecture across all CPU groups.

• Maximises compute efficiency on high-performance servers.

🚀 Performance Boost: Authentication loads scale better than ever.

🛰️ Smarter Replication Control

• Admins can assign replication priorities manually.

• Ideal for geo-distributed DCs and disaster recovery setups.

⚙️ Control Freaks Rejoice: You choose who replicates first.

📍 DC Locator Overhaul

• WINS and Mailslots are deprecated.

• Locator now uses NetBIOS and DNS—cleaner and more secure.

📡 Result: Faster logins, fewer resolution failures.

📈 New Monitoring Tools

• Performance counters added for:

  • LDAP Client Activity

  • DC Locator Logic

  • LSA Lookup Services

🧪 Troubleshooting Made Easy: More metrics, better insights.

🧬 Schema Version Update

• New schema files: sch89.ldf, sch90.ldf, sch91.ldf.

• AD LDS updated via MS-ADAM-Upgrade3.ldf.

🔧 Upgrade Tip: Always backup and test schema changes in staging.

🛡️ Management Plane Hardening

• Tier 0 asset protection emphasised.

• Virtualised DCs and remote admin ports are now audited more strictly.

🔥 Security Win: Reduced lateral movement risks.

🎯 TL;DR for the Busy Admin

Category	Key Upgrade	Why It Matters
Functional Levels	Version 10	Enables advanced features
Database	32K page size	Higher performance
Security	TLS 1.3, AES SHA-256/384	Stronger cryptography
Scalability	True NUMA support	Optimal use of modern hardware
Replication	Priority control	Customizable replication paths
DC Locator	No legacy protocols	Faster domain controller discovery
Monitoring	New counters	Easier performance tuning
Schema	Updated LDF files	Enables new features
Management Plane	Stricter auditing	Reduces lateral movement threats

🎙 Final Words

Whether you're planning a migration or optimising your AD ecosystem, Windows Server 2025 delivers the tools sysadmins need to thrive. Stay ahead of the curve, document everything, and automate where possible.

📌 Source

This blog is based on insights from the official

• Microsoft Windows Server Blog

• Windows Server 2025 Community Hub

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