Deploying and Managing Azure Domain Controllers for Enterprise

Deploying and managing Azure Domain Controllers for Enterprise requires careful planning and execution.

You can deploy Azure Domain Controllers using the Azure portal, Azure CLI, or PowerShell.

To ensure secure authentication, Azure Domain Controllers support Kerberos authentication.

For high availability, you can deploy multiple Azure Domain Controllers in an availability set.

This setup allows for automatic failover in case of a domain controller failure.

Azure Domain Controller Architecture and Planning involves several key considerations. You can define policies to govern the identity management group and subscriptions, deploying them through Azure Landing Zone options. These policies can be used to harden and manage resources in the identity subscription.

A dedicated subscription for identity is a best practice, containing Windows Server Active Directory Domain Services (AD DS) virtual machines or Azure Active Directory Domain Services. This subscription enables authentication and authorization for workloads within the landing zones.

For network architecture, consider placing domain controllers in a separate subnet, isolating the network through NSGs or firewalls. You can also configure the VM network interface (NIC) for each AD DS server with a static private IP address for full domain name service (DNS) support.

Here's a summary of the recommended network architecture:

As you plan your enterprise architecture, it's essential to consider the best practices for Azure Enterprise architecture. Microsoft has defined Enterprise scale best practices as part of their Cloud Adoption Framework (CAF), which provides prescriptive architecture guidance coupled with Azure best practices.

To manage identity, you can create a dedicated subscription for identity, which serves as a placeholder for Windows Server Active Directory Domain Services (AD DS) virtual machines or Azure Active Directory Domain Services. This subscription also enables authentication and authorization for workloads within the landing zones.

A management group can be used to contain a dedicated subscription for identity, which is a critical component of enterprise architecture. You can define policies to govern the identity management group and the subscriptions, which can be deployed through Azure Landing Zone options.

For VM sizing, you should consider the expected volume of authentication requests and start with the current on-premise specifications to match Azure VMs. Once deployed, monitor the utilization and scale up or down based on the actual load on the VMs.

Here are some key considerations for VM sizing:

You can use Azure Resize for VM size alterations to scale up or down as needed. Additionally, consider using a separate disk for the SysVol database, which can be created when you deploy the Azure VM. Set the Host Cache Preference setting on the data disk to None to avoid conflicts with AD DS requirements.

Deploy at least two VMs for ADDS, and consider using Azure HA options such as Availability Zones or Availability Sets to ensure high availability.

To configure a VM with static IP addresses, you need to set the IP address at the Virtual Network Interface. Go to VM Networking settings and click on "Networking".

In the right-hand menu, click on the Network Interface for the VM - you'll have a different name. Change the IP from "Dynamic" to "Static" and enter the IP address you want the domain controller to have, which must be an IP from the subnet you assigned to your virtual network.

Set the DNS server to the IP address of the domain controller. Click "Save" to restart the network interface and set the IP address.

Verify your IP settings by running ipconfig /all on the VM.

To configure Active Directory in Azure, you need to define a new AD site and configure all IP ranges to be part of that site. This ensures authentication requests from Azure VMs go directly to DCs in Azure without hitting on-prem DCs.

Don't use modern backup methods like snapshots or copy VHDs for domain controllers in Azure. Instead, perform regular system state backups and use Azure Backup, which is reliable and can be scheduled.

You should also avoid stopping or deallocating domain controllers from the Azure portal, as this can cause issues. Always restart the VM using the regular restart method from the VM itself.

To ensure your Active Directory configuration runs smoothly in Azure, follow these best practices.

First, define a new AD site in AD DS and configure all the IP ranges in Azure to be part of that AD site. This will ensure that authentication requests generated from Azure VMs go to DCs in Azure without going to on Prem.

Don't perform modern backup methods like snapshots or copy VHDs for domain controllers in Azure. Regular system state backup and Azure Backup are reliable and can be scheduled.

When you need to restart a domain controller, always use the regular restart method from the VM, not the Azure portal. Stopping or deallocating the domain controller from the portal can cause issues.

Here's what happens when you stop or deallocate a domain controller from the Azure portal:

You can configure your Azure AD Connect server to stick with a preferred domain controller, but it's not recommended as it disables DC failover and fault tolerance.

To do this, use the Azure AD Connect Synchronization Service Manager to configure preferred DCs. Select Connectors, right-click your Active Directory connector, and choose properties.

From the connector properties window, select Configure Directory Partitions, select your AD directory partition, and select the ‘Only use preferred domain controllers’ checkbox.

Click Configure and add the desired domain controllers to the list.

Extending On-Prem Active Directory can be a bit tricky, but it's a crucial step in managing your organization's identity and access.

To extend on-prem Active Directory, you'll need to deploy a new domain controller in a different location, which can be a branch office or a data center.

This allows users to access resources and authenticate to the network even when they're not physically in the main office.

The process involves creating a new site in Active Directory, which is a logical grouping of domain controllers that can communicate with each other.

A site is defined by a set of IP subnets, and when you create a new site, you'll need to specify the IP subnets that belong to it.

You'll also need to configure the DNS settings for the new site, which involves updating the DNS server with the new site's IP address.

This ensures that users can resolve names and access resources even when they're not in the main office.

When securing your Azure Domain Controller, it's essential to follow best practices. Always use Azure Disk encryption on your Domain controllers' OS Disk and SysVol Data disks.

To keep your data safe, you can use either Azure managed or customer-managed keys for encryption. If you opt for customer-managed keys, create a KeyVault and a Key to use when disk encryption.

Make sure to encrypt both your OS Disk and SysVol Disk using the same key. This will ensure your data is properly protected.

Using a separate subnet for your Domain controllers is also crucial for additional protection from your network. This is a recommended practice to prevent unauthorized access.

To achieve a quick replication of your AD changes to Office 365, there are two ways to go about it.

Make sure the change is replicated to all domain controllers before triggering an Azure AD Connect synchronization, or make the changes directly on the domain controller used by Azure AD Connect.

If you're running Easy365Manager, the Azure AD Connect synchronization is available in both user and group properties, so it's a simple one-click operation.

To ensure your changes are replicated to all domain controllers, you can use the RepAdmin command available in the AD tools, which involves running two commands for every DC to ensure both pull and push synchronization is made.

If you don't have Easy365Manager, you'll need to manually connect with PowerShell to your Azure AD Connect server and run a specific command to synchronize AD changes to Office 365.

Here are the two ways to synchronize AD changes to Office 365:

The second solution is often preferred because synchronizing all DC's can be a bit tedious.

To deploy a domain controller in Azure, you'll need to log in to the Azure Portal and create a new virtual machine. Make sure to select an Availability zone or Availability set for high availability.

Select the operating system and VM sizing for the domain controller, and remove public access to ensure security. You can choose between a Premium or standard SSD for the OS disk, but keep in mind that Premium has an SLA bound to the disk.

Encrypt the OS disk using a Platform managed key or Customer managed key, but if you choose the latter, you'll need to create a key vault and key first. For a domain controller, customer-managed keys are a good option.

Create another disk for the sysvol directory, and make sure to encrypt it using the same key as the OS disk. Configure host caching to none to avoid performance issues.

When setting up the virtual network, select a dedicated subnet for domain controllers and avoid adding a public IP address. You can also skip setting a Network security group for the NIC, as you'll be deploying an NSG for the whole subnet.

Configure tagging and create the VM, then log in to the VM to initialize the disk for the sysvol using Disk management – create volume. Don't forget to select this drive for the Sysvol when promoting the domain controller.