Microsoft Defender for Servers provides threat protection, vulnerability management, and security recommendations for Windows and Linux servers-both in Azure and hybrid/multi-cloud environments.
According to Microsoft Defender for Cloud documentation, enabling Defender for Servers coverage depends on how the server resource is hosted:
* Azure virtual machines (VMs) - are automatically onboarded using the built-in Azure Monitor agent and do not require Azure Arc.
* On-premises servers - must be onboarded through Azure Arc (Connected Machine agent) to connect to Azure before Defender for Servers can be enabled.
* Non-Azure cloud servers (AWS, GCP) - must also use Azure Arc to integrate with Defender for Cloud.
Now, applying this to the table:
Server
Location
Platform
Arc Needed?
Reason
Server1
On-premises
Windows Server
# Yes
Non-Azure, must be connected via Azure Arc
Server2
AWS
Linux
# Yes
Non-Azure, must be connected via Azure Arc
Server3
Azure
Windows Server
# No
Native Azure VM automatically protected
Server4
On-premises
Windows Server
# Yes
Non-Azure, must be connected via Azure Arc
# Therefore, the servers that require the Azure Arc agent are:
Server1, Server2, and Server4 only.