Section: [none]

Explanation:
Box 1:
The Autoscale scale out rule increases the number of VMs by 2 if the CPU threshold is 80% or higher. The initial instance count is 4 and rises to 6 when the 2 extra instances of VMs are added.
Box 2:
The Autoscale scale in rule decreases the number of VMs by 4 if the CPU threshold is 30% or lower. The initial instance count is 4 and thus cannot be reduced to 0 as the minimum instances is set to 2. Instances are only added when the CPU threshold reaches 80%.
References:
https://docs.microsoft.com/en-us/azure/azure-monitor/platform/autoscale-overview
https://docs.microsoft.com/en-us/azure/azure-monitor/platform/autoscale-best-practices
https://docs.microsoft.com/en-us/azure/azure-monitor/platform/autoscale-common-scale-patterns

Explanation:
IP forwarding enables the virtual machine a network interface is attached to:
* Receive network traffic not destined for one of the IP addresses assigned to any of the IP configurations assigned to the network interface.
* Send network traffic with a different source IP address than the one assigned to one of a network interface's IP configurations.
The setting must be enabled for every network interface that is attached to the virtual machine that receives traffic that the virtual machine needs to forward. A virtual machine can forward traffic whether it has multiple network interfaces or a single network interface attached to it.
Box 1: Yes
The routing table allows connections from VM3 to VM1 and VM2. And as IP forwarding is enabled on VM3, VM3 can connect to VM1.
Box 2: No
VM3, which has IP forwarding, must be turned on, in order for VM2 to connect to VM1.
Box 3: Yes
The routing table allows connections from VM1 and VM2 to VM3. IP forwarding on VM3 allows VM1 to connect to VM2 via VM3.
References:
https://docs.microsoft.com/en-us/azure/virtual-network/virtual-networks-udr-overview
https://www.quora.com/What-is-IP-forwarding

Explanation:
Box 1: Join the VMs to a new domain controller VM in Azure
Azure provides two solutions for implementing directory and identity services in Azure:
* (Used in this scenario) Extend your existing on-premises Active Directory infrastructure to Azure, by deploying a VM in Azure that runs AD DS as a Domain Controller. This architecture is more common when the on-premises network and the Azure virtual network (VNet) are connected by a VPN or ExpressRoute connection.
* Use Azure AD to create an Active Directory domain in the cloud and connect it to your on-premises Active Directory domain. Azure AD Connect integrates your on-premises directories with Azure AD.
Box 2: Set up VPN connectivity.
This architecture is more common when the on-premises network and the Azure virtual network (VNet) are connected by a VPN or ExpressRoute connection.
References:
https://docs.microsoft.com/en-us/azure/architecture/reference-architectures/identity/

Section: [none]
Explanation:
We should use a Conditional Access policy.
Note: There are two ways to secure user sign-in events by requiring multi-factor authentication in Azure AD.
The first, and preferred, option is to set up a Conditional Access policy that requires multi-factor authentication under certain conditions. The second option is to enable each user for Azure Multi-Factor Authentication. When users are enabled individually, they perform multi-factor authentication each time they sign in (with some exceptions, such as when they sign in from trusted IP addresses or when the remembered devices feature is turned on).
Enabling Azure Multi-Factor Authentication using Conditional Access policies is the recommended approach.
Changing user states is no longer recommended unless your licenses don't include Conditional Access as it requires users to perform MFA every time they sign in.
Reference:
https://docs.microsoft.com/en-us/azure/active-directory/authentication/howto-mfa-userstates