Microsoft AZ-104 - Microsoft Azure Administrator

Box 1: Create a virtual network gateway and a local network gateway.

Azure VPN gateway. The VPN gateway service enables you to connect the VNet to the on-premises network through a VPN appliance. For more information, see Connect an on-premises network to a Microsoft Azure virtual network. The VPN gateway includes the following elements:

Virtual network gateway. A resource that provides a virtual VPN appliance for the VNet. It is responsible for routing traffic from the on-premises network to the VNet.

Local network gateway. An abstraction of the on-premises VPN appliance. Network traffic from the cloud application to the on-premises network is routed through this gateway.

Connection. The connection has properties that specify the connection type (IPSec) and the key shared with the on-premises VPN appliance to encrypt traffic.

Gateway subnet. The virtual network gateway is held in its own subnet, which is subject to various requirements, described in the Recommendations section below.

Box 2: Configure a site-to-site VPN connection

On premises create a site-to-site connection for the virtual network gateway and the local network gateway.

Scenario: Connect the New York office to VNet1 over the Internet by using an encrypted connection.

Scenario: Litware must meet technical requirements including:

Ensure that VM3 can establish outbound connections over TCP port 8080 to the applications servers in the Montreal office.

IP flow verify checks if a packet is allowed or denied to or from a virtual machine. The information consists of direction, protocol, local IP, remote IP, local port, and remote port. If the packet is denied by a security group, the name of the rule that denied the packet is returned. While any source or destination IP can be chosen, IP flow verify helps administrators quickly diagnose connectivity issues from or to the internet and from or to the on-premises environment.

To enable communication between virtual machines (VMs) located in different virtual networks (VNets) in Azure, the most efficient and recommended approach—according to Microsoft Azure Administrator documentation—is to use VNet peering.

1. Background and Scenario Analysis

From the case study:

VM1 and VM4 are located in different VNets (VNET1 and VNET3).

The requirement is to ensure that VM1 can communicate with VM4.

The solution must minimize administrative effort and cost.

2. Microsoft Documentation Insight: VNet Peering

According to Microsoft Learn: “Virtual network peering”:

“Virtual network peering seamlessly connects two Azure virtual networks. The virtual networks appear as one for connectivity purposes. Traffic between peered virtual networks uses private IP addresses, as if they were part of the same network, and the traffic stays entirely on the Microsoft backbone network.”

Key characteristics of VNet peering:

Enables private IP connectivity between resources across peered VNets.

No need to deploy or maintain gateways (unlike VPN gateways).

Provides low latency and high bandwidth.

Supports transitive routing through additional configurations.

Minimal administrative overhead — peering can be created with just a few clicks or PowerShell/CLI commands.

3. Why the Other Options Are Incorrect

A. Create a user-defined route (UDR) from VNET1 to VNET3.

❌ A UDR alone cannot enable connectivity between VNets unless a gateway or peering already exists. Without a connection path, a route has no effect.

B. Assign VM4 an IP address of 10.0.1.5/24.

❌ This would attempt to place VM4 in the same subnet as VM1, but cross-VNet subnet IP assignment is not possible in Azure. Each VNet has its own isolated address space.

D. Create an NSG and associate it with VM1 and VM4.

❌ Network Security Groups control traffic filtering within or between existing network connections. They do not create connectivity between isolated VNets.

4. Why Peering Is the Correct and Simplest Solution

Establishing VNet peering between VNET1 and VNET3 will:

Instantly enable bidirectional private IP communication between VM1 and VM4.

Minimize administrative effort (no gateways, routing tables, or IP reconfiguration).

Maintain security and performance through Microsoft’s internal backbone.

Avoid additional costs compared to deploying VPN gateways.

5. Implementation Summary

Steps to configure:

In the Azure Portal, go to VNET1 → Peerings → Add.

Choose VNET3 as the peer virtual network.

Enable Allow virtual network access in both directions.

Once completed, both VMs (VM1 and VM4) will communicate using their private IPs.

Final Verified Answer: ✅ C. Establish peering between VNET1 and VNET3

References (Microsoft Official Documentation):

Microsoft Learn — Virtual network peering overview

Microsoft Learn — Create, change, or delete a virtual network peering

Microsoft Learn — Azure virtual network connectivity options and recommendations

https://docs.microsoft.com/en-us/azure/role-based-access-control/tutorial-custom-role-powershell

Get-AzRoleDefinition -Name " Reader " | ConvertTo-Json

https://docs.microsoft.com/en-us/powershell/module/az.resources/get-azroledefinition?view=azps-5.9.0

https://docs.microsoft.com/en-us/azure/role-based-access-control/tutorial-custom-role-powershell

https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.utility/convertto-json?view=powershell-7.1

https://docs.microsoft.com/en-us/powershell/module/azuread/get-azureaddirectoryrole?view=azureadps-2.0