VNet creation and address space in Azure - Step-by-Step Execution

Process Flow - VNet creation and address space

Start VNet Creation

↓

Define VNet Name

↓

Specify Address Space

↓

Validate Address Space

↓

Create VNet with Address Space

↓

VNet Ready for Use

The flow shows creating a virtual network by naming it, setting its address space, validating it, and then creating it for use.

Execution Sample

Azure

az network vnet create --name MyVNet --resource-group MyResourceGroup --address-prefix 10.0.0.0/16

This command creates a virtual network named MyVNet with the address space 10.0.0.0/16 in the specified resource group.

Process Table

Step	Action	Input	Validation	Result
1	Start VNet creation	N/A	N/A	Ready to define VNet
2	Define VNet name	MyVNet	Name valid	Name accepted
3	Specify address space	10.0.0.0/16	CIDR valid, no overlap	Address space accepted
4	Validate address space	10.0.0.0/16	Valid CIDR block	Validation successful
5	Create VNet	Name: MyVNet, Address: 10.0.0.0/16	N/A	VNet created successfully
6	VNet ready	N/A	N/A	VNet available for resources

💡 VNet creation completes after successful validation and creation steps.

Status Tracker

Variable	Start	After Step 2	After Step 3	After Step 5	Final
VNetName	undefined	MyVNet	MyVNet	MyVNet	MyVNet
AddressSpace	undefined	undefined	10.0.0.0/16	10.0.0.0/16	10.0.0.0/16
VNetStatus	not created	not created	not created	created	available

Key Moments - 3 Insights

Why must the address space be a valid CIDR block?

Because the address space defines the IP range for the VNet, it must be a valid CIDR to ensure proper network routing and avoid conflicts, as shown in step 4 of the execution table.

What happens if the VNet name is invalid?

The creation process stops at step 2 because the name must follow Azure naming rules; invalid names prevent proceeding to address space specification.

Can the address space overlap with existing VNets?

No, overlapping address spaces cause conflicts. Validation in step 3 ensures no overlap before creation.

Visual Quiz - 3 Questions

Look at the execution table, what is the address space after step 3?

A undefined

B 10.0.0.0/16

C 192.168.1.0/24

D N/A

💡 Hint

Check the 'AddressSpace' variable in variable_tracker after step 3.

At which step does the VNet status change to 'created'?

A Step 5

B Step 3

C Step 2

D Step 6

💡 Hint

Look at the 'VNetStatus' variable in variable_tracker and the execution_table result column.

If the address space was invalid, what would happen in the execution flow?

A Name validation fails at step 2

B Creation proceeds normally

C Validation fails at step 4 and stops

D VNet is created with default address space

💡 Hint

Refer to step 4 in the execution_table where address space validation occurs.

Concept Snapshot

VNet creation requires a unique name and a valid address space in CIDR format.
The address space defines the IP range for resources.
Azure validates the address space for correctness and overlap.
After validation, the VNet is created and ready for use.
Use Azure CLI command: az network vnet create --name <name> --resource-group <group> --address-prefix <CIDR>

Full Transcript

Creating a Virtual Network (VNet) in Azure starts by choosing a name and specifying an address space in CIDR format. The address space is the range of IP addresses the VNet will use. Azure checks that the name is valid and that the address space is a proper CIDR block without overlapping existing networks. Once validated, the VNet is created and becomes available for deploying resources. This process ensures network organization and avoids IP conflicts.