Quickstart: Create a public load balancer to load balance VMs using the Azure portal

Article
08/12/2024

Get started with Azure Load Balancer by using the Azure portal to create a public load balancer for a backend pool with two virtual machines. Other resources include Azure Bastion, NAT Gateway, a virtual network, and the required subnets.

Prerequisites

An Azure account with an active subscription. Create a trial subscription.

Create NAT gateway

In this section, you create a NAT gateway for outbound internet access for resources in the virtual network. For other options for outbound rules, check out Network Address Translation (SNAT) for outbound connections

Sign in to the Azure portal.
In the search box at the top of the portal, enter NAT gateway. Select NAT gateways in the search results.
Select + Create.

In the Basics tab of Create network address translation (NAT) gateway enter or select the following information:

Setting	Value
Project details
Subscription	Select your subscription.
Resource group	Select Create new. Enter load-balancer-rg in Name. Select OK.
Instance details
NAT gateway name	Enter lb-nat-gateway.
Region	Select China North 3.
Availability zone	Select No zone.
Idle timeout (minutes)	Enter 15.

Select the Outbound IP tab or select the Next: Outbound IP button at the bottom of the page.
Select Create a new public IP address under Public IP addresses.
Enter nat-gw-public-ip in Name in Add a public IP address.
Select OK.
Select the blue Review + create button at the bottom of the page, or select the Review + create tab.
Select Create.

Create a virtual network and bastion host

In this section, you create a virtual network with a resource subnet, an Azure Bastion subnet, and an Azure Bastion host.

Important

Hourly pricing starts from the moment that Bastion is deployed, regardless of outbound data usage. For more information, see Pricing and SKUs. If you're deploying Bastion as part of a tutorial or test, we recommend that you delete this resource after you finish using it.

In the portal, search for and select Virtual networks.
On the Virtual networks page, select + Create.

On the Basics tab of Create virtual network, enter or select the following information:

Setting	Value
Project details
Subscription	Select your subscription.
Resource group	Select load-balancer-rg from the dropdown or Create new if it doesn't exist. Enter load-balancer-rg in Name. Select OK.
Instance details
Name	Enter lb-vnet.
Region	Select China North 3

Screenshot of Basics tab of Create virtual network in the Azure portal.

Select the Security tab or Next button at the bottom of the page.

Under Azure Bastion, enter or select the following information:

Setting	Value
Azure Bastion
Enable Azure Bastion	Select checkbox.
Azure Bastion host name	Enter lb-bastion.
Azure Bastion public IP address	Select Create new. Enter lb-bastion-ip in Name. Select OK.

Select the IP addresses tab, or Next at the bottom of the page.

On Create virtual network page, enter or select the following information:

Setting	Value
Add IPv4 address space
IPv4 address space	Enter 10.0.0.0/16 (65,356 addresses).
Subnets	Select the default subnet link to edit.
Edit subnet
Subnet purpose	Leave the default Default.
Name	Enter backend-subnet.
Starting address	Enter 10.0.0.0.
Subnet size	Enter /24(256 addresses).
Security
NAT Gateway	Select lb-nat-gateway.

Screenshot of default subnet rename and configuration.

Select Save.
Select Review + create at the bottom of the screen, and when validation passes, select Create.

Create load balancer

In this section, you create a zone redundant load balancer that load balances virtual machines. With zone-redundancy, one or more availability zones can fail and the data path survives as long as one zone in the region remains healthy.

During the creation of the load balancer, you configure:

Frontend IP address
Backend pool
Inbound load-balancing rules
Health probe

In the search box at the top of the portal, enter Load balancer. Select Load balancers in the search results.
In the Load balancer page, select + Create.

In the Basics tab of the Create load balancer page, enter or select the following information:

Setting	Value
Project details
Subscription	Select your subscription
Resource group	Select load-balancer-rg
Instance details
Name	Enter load-balancer
Region	Select China East
SKU	Leave the default Standard
Type	Select Public
Tier	Leave the default Regional

Screenshot of create standard load balancer basics tab.

Select Next: Frontend IP configuration at the bottom of the page.
In Frontend IP configuration, select + Add a frontend IP configuration.
Enter lb-frontend in Name.
Select IPv4 for the IP version.
Select IP address for the IP type.

Note

For more information on IP prefixes, see Azure Public IP prefix.
Select Create new in Public IP address.
In Add a public IP address, enter lb-frontend-ip for Name.
Select Zone-redundant in Availability zone.

Note

In regions with Availability Zones, you have the option to select no-zone (default option), a specific zone, or zone-redundant. The choice will depend on your specific domain failure requirements. In regions without Availability Zones, this field won't appear.
For more information on availability zones, see Availability zones overview.
Select OK.
Select Add.
Select Next: Backend pools at the bottom of the page.
In the Backend pools tab, select + Add a backend pool.
Enter lb-backend-pool for Name in Add backend pool.
Select lb-vnet in Virtual network.
Select IP Address for Backend Pool Configuration.
Select Save.
Select Next: Inbound rules at the bottom of the page.
Under Load balancing rule in the Inbound rules tab, select + Add a load balancing rule.

In Add load balancing rule, enter or select the following information:

Setting	Value
Name	Enter lb-HTTP-rule
IP Version	Select IPv4 or IPv6 depending on your requirements
Frontend IP address	Select lb-frontend (To be created)
Backend pool	Select lb-backend-pool
Protocol	Select TCP
Port	Enter 80
Backend port	Enter 80
Health probe	Select Create new. In Name, enter lb-health-probe. Select HTTP in Protocol. Leave the rest of the defaults, and select Save.
Session persistence	Select None.
Idle timeout (minutes)	Enter or select 15
Enable TCP reset	Select checkbox
Enable Floating IP	Leave unchecked
Outbound source network address translation (SNAT)	Leave the default of (Recommended) Use outbound rules to provide backend pool members access to the internet.

Select Save.
Select the blue Review + create button at the bottom of the page.
Select Create.

Note

In this example we'll create a NAT gateway to provide outbound Internet access. The outbound rules tab in the configuration is bypassed as it's optional and isn't needed with the NAT gateway. For more information on Azure NAT gateway, see What is Azure Virtual Network NAT? For more information about outbound connections in Azure, see Source Network Address Translation (SNAT) for outbound connections

Create virtual machines

In this section, you create two VMs (lb-vm1 and lb-VM2) in two different zones (Zone 1 and Zone 2).

These VMs are added to the backend pool of the load balancer that was created earlier.

In the search box at the top of the portal, enter Virtual machine. Select Virtual machines in the search results.
In Virtual machines, select + Create > Azure virtual machine.

In Create a virtual machine, enter or select the following values in the Basics tab:

Setting	Value
Project Details
Subscription	Select your Azure subscription
Resource Group	Select load-balancer-rg
Instance details
Virtual machine name	Enter lb-VM1
Region	Select (Asia Pacific) China North 3
Availability Options	Select Availability zones
Availability zone	Select Zone 1
Security type	Select Standard.
Image	Select Windows Server 2019 Datacenter - Gen2
Size	Choose VM size or take default setting
Administrator account
Username	Enter a username
Password	Enter a password
Confirm password	Reenter password
Inbound port rules
Public inbound ports	Select None

Select the Networking tab, or select Next: Disks, then Next: Networking.

In the Networking tab, select or enter the following information:

Setting	Value
Network interface
Virtual network	Select lb-vnet
Subnet	Select backend-subnet
Public IP	Select None.
NIC network security group	Select Advanced
Configure network security group	Skip this setting until the rest of the settings are completed. Complete after Select a backend pool.
Delete NIC when VM is deleted	Leave the default of unselected.
Accelerated networking	Leave the default of selected.
Load balancing
Load balancing options
Load-balancing options	Select Azure load balancer
Select a load balancer	Select load-balancer
Select a backend pool	Select lb-backend-pool
Configure network security group	Select Create new. In the Create network security group, enter lb-NSG in Name. Under Inbound rules, select +Add an inbound rule. In Service, select HTTP. Under Priority, enter 100. In Name, enter lb-NSG-Rule Select Add Select OK

Select Review + create.
Review the settings, and then select Create.
Follow the steps 1 through 7 to create another VM with the following values and all the other settings the same as lb-VM1:

Setting VM 2

Name lb-VM2

Availability zone Zone 2

Network security group Select the existing lb-NSG

Setting	VM 2
Name	lb-VM2
Availability zone	Zone 2
Network security group	Select the existing lb-NSG

Note

Azure provides a default outbound access IP for VMs that either aren't assigned a public IP address or are in the backend pool of an internal basic Azure load balancer. The default outbound access IP mechanism provides an outbound IP address that isn't configurable.

The default outbound access IP is disabled when one of the following events happens:

A public IP address is assigned to the VM.
The VM is placed in the backend pool of a standard load balancer, with or without outbound rules.
An Azure NAT Gateway resource is assigned to the subnet of the VM.

VMs that you create by using virtual machine scale sets in flexible orchestration mode don't have default outbound access.

For more information about outbound connections in Azure, see Default outbound access in Azure and Use Source Network Address Translation (SNAT) for outbound connections.

Install IIS

In the search box at the top of the portal, enter Virtual machine. Select Virtual machines in the search results.
Select lb-VM1.
On the Overview page, select Connect, then Bastion.
Enter the username and password entered during VM creation.
Select Connect.
On the server desktop, navigate to Start > Windows PowerShell > Windows PowerShell.

In the PowerShell Window, run the following commands to:

Install the IIS server.
Remove the default iisstart.htm file.
Add a new iisstart.htm file that displays the name of the VM:

 # Install IIS server role
 Install-WindowsFeature -name Web-Server -IncludeManagementTools

 # Remove default htm file
 Remove-Item  C:\inetpub\wwwroot\iisstart.htm

 # Add a new htm file that displays server name
 Add-Content -Path "C:\inetpub\wwwroot\iisstart.htm" -Value $("Hello World from " + $env:computername)

Close the Bastion session with lb-VM1.
Repeat steps 1 to 8 to install IIS and the updated iisstart.htm file on lb-VM2.

Test the load balancer

In the search box at the top of the page, enter Public IP. Select Public IP addresses in the search results.
In Public IP addresses, select frontend-ip.
Copy the item in IP address. Paste the public IP into the address bar of your browser. The custom VM page of the IIS Web server is displayed in the browser.

Clean up resources

When no longer needed, delete the resource group, load balancer, and all related resources. To do so, select the resource group load-balancer-rg that contains the resources and then select Delete.

Next steps

In this quickstart, you:

Created an Azure Load Balancer
Attached 2 VMs to the load balancer
Tested the load balancer

To learn more about Azure Load Balancer, continue to:

What is Azure Load Balancer?