You need to ensure that VM1 can communicate with VM4. The solution must minimize administrative effort. What should you do?

Virtual machines in different virtual networks (VNETs) cannot communicate by default. The most straightforward and administratively simple method to enable communication between VNET1 and VNET3 is to use VNet peering. VNet peering connects two virtual networks, allowing traffic to flow between them privately over the Microsoft backbone network as if they were a single network. Since the address spaces of VNET1 (10.0.0.0/16) and VNET3 (10.1.0.0/16) do not overlap, peering is a valid and optimal solution that directly meets the requirement with minimal configuration.

A. A user-defined route (UDR) only directs traffic to a specific next hop (like a gateway or virtual appliance); it does not create the underlying connectivity path between the VNETs.
B. A Network Security Group (NSG) acts as a firewall to filter traffic. It can permit or deny communication but cannot establish the initial connectivity between separate virtual networks.
C. A virtual machine must be assigned an IP address from the address space of the virtual network it resides in. Assigning an IP from VNET1's range to a VM in VNET3 is not possible.

1. Microsoft Learn | Azure Virtual Network Documentation: "Virtual network peering enables you to seamlessly connect two or more Azure virtual networks. The virtual networks appear as one for connectivity purposes. The traffic between virtual machines in peered virtual networks uses the Microsoft backbone infrastructure."

Source: Azure virtual network peering

Section: "Connectivity".

2. Microsoft Learn | Azure Virtual Network Documentation: "Azure routes traffic between subnets

connected virtual networks

on-premises networks

and the Internet

by default. You can override Azure's default routing by creating a route table... A route table contains routes

also known as user-defined routes (UDR)."

Source: Virtual network traffic routing

Section: "User-defined".

3. Microsoft Learn | Azure Virtual Network Documentation: "A network security group contains security rules that allow or deny inbound network traffic to

or outbound network traffic from

several types of Azure resources. For each rule

you can specify source and destination

port

and protocol."

Source: Network security groups

Section: "Introduction".

4. Microsoft Learn | Azure Virtual Network Documentation: "You assign the following IP address settings to an Azure virtual network: Address space... Each subnet within a VNet must have an address space

specified in CIDR format

that's a subrange of the VNet's address space."

Source: Public and private IP addressing in Azure

Section: "Virtual networks".