Enable MFA for Azure AD Users

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Common use cases to require Azure AD Multi-Factor Authentication include:

• For administrators
• To specific applications
• For all users
• For Azure management
• From network locations you don't trust

Plan User Session Lifetime

Plan User Registration

Per-User MFA vs Conditional Access Based MFA

In your tenant, you can enable MFA on a per-user basis. In this scenario, your users perform MFA each time they sign in, with some exceptions, such as when they sign in from trusted IP addresses or when the remember MFA on trusted devices feature is turned on. 

• https://learn.microsoft.com/en-us/azure/active-directory/authentication/howto-mfa-userstates

This recommendation shows up if:

• You have per-user MFA configured for at least 5% of your users.
• Conditional Access policies are active for more than 1% of your users (indicating familiarity with CA policies).

# Connect to tenant
Connect-MsolService

# Sets the MFA requirement state
function Set-MfaState {
 [CmdletBinding()]
 param(
 [Parameter(ValueFromPipelineByPropertyName=$True)]
 $ObjectId,
 [Parameter(ValueFromPipelineByPropertyName=$True)]
 $UserPrincipalName,
 [ValidateSet("Disabled","Enabled","Enforced")]
 $State
 )
 Process {
 Write-Verbose ("Setting MFA state for user '{0}' to '{1}'." -f $ObjectId, $State)
 $Requirements = @()
 if ($State -ne "Disabled") {
 $Requirement =
 [Microsoft.Online.Administration.StrongAuthenticationRequirement]::new()
 $Requirement.RelyingParty = "*"
 $Requirement.State = $State
 $Requirements += $Requirement
 }
 Set-MsolUser -ObjectId $ObjectId -UserPrincipalName $UserPrincipalName `
  -StrongAuthenticationRequirements $Requirements
 }
}
# Disable MFA for all users
Get-MsolUser -All | Set-MfaState -State Disabled

Your Azure AD Multi-Factor Authentication rollout plan should include a pilot deployment followed by deployment waves that are within your support capacity. Begin your rollout by applying your Conditional Access policies to a small group of pilot users. After evaluating the effect on the pilot users, process used, and registration behaviors, you can either add more groups to the policy or add more users to the existing groups.

Follow the steps below:

1. Meet the necessary prerequisites
2. Configure chosen authentication methods
3. Configure your Conditional Access policies
4. Configure session lifetime settings
5. Configure Azure AD MFA registration policies