It can take some research and tests to understand the difference between different Azure AD join types.

I summarised some key differences in the following.

Difference between	Azure AD registered	Azure AD joined	Hybrid Azure AD joined
Primary audience	Bring your own device (BYOD) Mobile devices	Organizational computer	Organizational computer
OS	Windows 10, iOS, Android, and MacOS	Windows 10 devices (except Windows 10 Home) Windows Server 2019 Virtual Machines running in Azure (except Server core)	Windows 10, 8.1 and 7 Windows Server 2008/R2, 2012/R2, 2016 and 2019
Device sign in options	Local account Windows Hello	Organizational account in Azure AD Windows Hello for Business	Organizational account in on-prem AD Windows Hello for Business
Sign in authenticate to	Local computer	Azure AD	On-prem domain controller
Device management	MDM (Intune)	MDM (Intune)	MDM (Intune) and Group policy
SSO	SSO to cloud resources	SSO to both cloud and on-premises resources	SSO to both cloud and on-premises resources
Self-service Password Reset	Only for local account	For Organizational account at login/lock screen	For Organizational account at login/lock screen

As more and more staff work from home, IT starts to consider solutions to allow remote identity management without relying on line-of-sight to domain controllers. so:

If you want to login to a computer by authenticating to Azure AD, you will need to unbind the computer from on-prem AD then bind to Azure AD. A hybrid Azure AD joined computer will still authenticate to your domain controller
Microsoft recommends to use the MDM-only approach to manage all Azure AD joined devices, instead of co-management with SCCM.

Overview

In Azure, Network Security Group (NSG) is a basic firewall containing a list of security rules.

NSG can be associated to subnets, individual NICs or both.

By default the outbound NSG for a subnet allows all outbound traffic, which is not secure for servers.

There are discussions [1] [2] on how to limit the outbound traffic while allowing traffic to Azure infrastructures required by different services like Windows updates.

I found that existing methods created hundreds of rules which are difficult to maintain. This post introduces a method to create a single rule the allows the outbound traffic to all Azure IP ranges.

Implementation

Code – new

The following script uses Azure Powershell az.

As it doesn’t support GUI yet so there are more parameters to set before running it.

# JZ 20190712

# This script creates a rule to allow outbound traffic to all Azure IPs

# Note: before running, delete the existing NSG rule named $nsgName at priority $priorityNumber

# Parameters

$subscriptionID = "00000000-aaaa-bbbb-cccc-0000000000"

$selectedRegions = "australiaeast","australiasoutheast","australiac","australiac2"

$rgName = "Resource-group-name"

$nsgName = "network-security-group-name"

$ruleName = "Allow_Outbound_to_Azure_IPs"

$priorityNumber = 200

# Sign-in with Azure account credentials

Connect-AzAccount

# Select Azure Subscription

Select-AzSubscription -SubscriptionId $subscriptionID

# Download current list of Azure Public IP ranges

# See https://www.microsoft.com/en-in/download/confirmation.aspx?id=41653 for latest list

$downloadUri = "https://www.microsoft.com/en-in/download/confirmation.aspx?id=41653"

$downloadPage = Invoke-WebRequest -Uri $downloadUri

$xmlFileUri = ($downloadPage.RawContent.Split('"') -like "https://*PublicIps*")[0]

$response = Invoke-WebRequest -Uri $xmlFileUri

# Get list of regions & public IP ranges

[xml]$xmlResponse = [System.Text.Encoding]::UTF8.GetString($response.Content)

$regions = $xmlResponse.AzurePublicIpAddresses.Region

$ipRange = ( $regions | where-object Name -In $selectedRegions ).IpRange

# combine all IPs

# They need to be in an array format to use NSG augmented security rules

$all_subnets=""

ForEach ($subnet in $ipRange.Subnet) {

$all_subnets+=$subnet

$all_subnets+=","

}

$all_subnets=$all_subnets.trimend(",")

$test=$all_subnets.split(",")

# Add the NSG rules

$nsg = Get-AzNetworkSecurityGroup -Name $nsgName -ResourceGroupName $rgName

Add-AzNetworkSecurityRuleConfig -NetworkSecurityGroup $nsg -Name $ruleName `

-Access Allow -Protocol * -Direction Outbound -Priority $priorityNumber `

-SourceAddressPrefix * -SourcePortRange * `

-DestinationAddressPrefix $test -DestinationPortRange *

Set-AzNetworkSecurityGroup -NetworkSecurityGroup $nsg

Code – old

The following script uses Azure Powershell.

Adjust the 3 parameters before running it.

# JZ 20180810

# This script creates a rule to allow outbound traffic to all Azure IPs

# Note: before running, delete the existing NSG rule named $nsgName at priority $priorityNumber

# Parameters

$nsgName = "VLAN-webDMZ-Security-Group"

$ruleName = "Allow_Outbound_to_Azure_IPs"

$priorityNumber = 200

# Sign-in with Azure account credentials

# Select Azure Subscription

$subscriptionId =

(Get-AzureRmSubscription |

Out-GridView `

-Title "Select an Azure Subscription ..." `

-PassThru).SubscriptionId

Select-AzureRmSubscription -SubscriptionId $subscriptionId

# Select Azure Resource Group

$rgName =

(Get-AzureRmResourceGroup |

Out-GridView `

-Title "Select an Azure Resource Group ..." `

-PassThru).ResourceGroupName

# Download current list of Azure Public IP ranges

# See https://www.microsoft.com/en-in/download/confirmation.aspx?id=41653 for latest list

$downloadUri = "https://www.microsoft.com/en-in/download/confirmation.aspx?id=41653"

$downloadPage = Invoke-WebRequest -Uri $downloadUri

$xmlFileUri = ($downloadPage.RawContent.Split('"') -like "https://*PublicIps*")[0]

$response = Invoke-WebRequest -Uri $xmlFileUri

# Get list of regions & public IP ranges

[xml]$xmlResponse = [System.Text.Encoding]::UTF8.GetString($response.Content)

$regions = $xmlResponse.AzurePublicIpAddresses.Region

# Select Azure regions for which to define NSG rules

$selectedRegions =

$regions.Name |

Out-GridView `

-Title "Select Azure Datacenter Regions ..." `

-PassThru

$ipRange = ( $regions | where-object Name -In $selectedRegions ).IpRange

# combine all IPs

# They need to be in an array format to use NSG augmented security rules

$all_subnets=""

ForEach ($subnet in $ipRange.Subnet) {

$all_subnets+=$subnet

$all_subnets+=","

}

$all_subnets=$all_subnets.trimend(",")

$test=$all_subnets.split(",")

# Add the NSG rules

$nsg = Get-AzureRmNetworkSecurityGroup -Name $nsgName -ResourceGroupName $rgName

Add-AzureRmNetworkSecurityRuleConfig -NetworkSecurityGroup $nsg -Name $ruleName `

-Access Allow -Protocol * -Direction Outbound -Priority $priorityNumber `

-SourceAddressPrefix * -SourcePortRange * `

-DestinationAddressPrefix $test -DestinationPortRange *

Set-AzureRmNetworkSecurityGroup -NetworkSecurityGroup $nsg

After running the code

After defining these Azure-related outbound rules, you may need to add some additional rules to permit outbound access to other legitimate non-Azure services, such as

public DNS servers
email services
kms.core.windows.net:1688
APIs,
etc, that your applications may also need to access

Then, you can create a rule at the end of the NSG to block all outbound traffic.

Reference

[1] https://blogs.technet.microsoft.com/keithmayer/2016/01/12/step-by-step-automate-building-outbound-network-security-groups-rules-via-azure-resource-manager-arm-and-powershell/

[2] https://serverfault.com/questions/888645/nsg-block-all-outbount-internet-traffic

IT – By Tea

AirPlay in Enterprise Networks

Auto-create Default Outbound NSG for Servers in Azure

Exchange – “send as” and “send on behalf” records

Different Azure AD Join Types

TCP saves water?

When an update is available

Auto-create Default Outbound NSG for Servers in Azure

Overview

Implementation

Code – new

Code – old

After running the code

Reference