Tutorial: Load balance multiple IP configurations using the Azure portal

Article
08/12/2024

To host multiple websites, you can use another network interface associated with a virtual machine. Azure Load Balancer supports deployment of load-balancing to support the high availability of the websites.

In this tutorial, you learn how to:

Create and configure a virtual network, subnet, and NAT gateway.
Create two Windows server virtual machines
Create a secondary NIC and network configurations for each virtual machine
Create two Internet Information Server (IIS) websites on each virtual machine
Bind the websites to the network configurations
Create and configure an Azure Load Balancer
Test the load balancer

Prerequisites

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

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.

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.

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 virtual machines

In this section, you create two virtual machines to host the IIS websites.

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.

In Create virtual machine, enter or select the following information:

Setting	Value
Project Details
Subscription	Select your Azure subscription
Resource Group	Select load-balancer-rg
Instance details
Virtual machine name	Enter myVM1
Region	Select China North 3
Availability Options	Select Availability zones
Availability zone	Select 1
Security type	Leave the default of Standard.
Image	Select Windows Server 2022 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:

Setting	Value
Network interface
Virtual network	Select myVNet.
Subnet	Select backend-subnet(10.1.0.0/24)
Public IP	Select None.
NIC network security group	Select Advanced
Configure network security group	Select Create new. In Create network security group, enter myNSG in Name. In Inbound rules, select +Add an inbound rule. In Service, select HTTP. In Priority, enter 100. In Name, enter myNSGrule Select Add Select OK

Select Review + create.
Review the settings, and then select Create.
Follow the steps 1 to 7 to create another VM with the following values and all the other settings the same as myVM1:

Setting VM 2

Name myVM2

Availability zone 2

Network security group Select the existing myNSG

Setting	VM 2
Name	myVM2
Availability zone	2
Network security group	Select the existing myNSG

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.

Create secondary network configurations

In this section, you change the private IP address of the existing NIC of each virtual machine to Static. Next, you add a new NIC resource to each virtual machine with a Static private IP address configuration.

For more information on configuring floating IP in the virtual machine configuration, see Floating IP Guest OS configuration.

In the search box at the top of the portal, enter Virtual machine. Select Virtual machines in the search results.
Select myVM1.
Stop the virtual machine if it's running.
Select Networking in Settings.
In Networking, select the name of the network interface next to Network interface. The network interface begins with the name of the VM and has a random number assigned. In this example, myVM1266.
In the network interface page, select IP configurations in Settings.
In IP configurations, select ipconfig1.
Select Static in Assignment in the ipconfig1 configuration.
Select Save.
Return to the Overview page of myVM1.
Select Networking in Settings.
In the Networking page, select Attach network interface.
In Attach network interface, select Create and attach network interface.

In Create network interface, enter or select the following information:

Setting	Value
Project details
Resource group	Select load-balancer-rg.
Network interface
Name	Enter myVM1NIC2
Subnet	Select backend-subnet (10.1.0.0/24).
NIC network security group	Select Advanced.
Configure network security group	Select myNSG.
Private IP address assignment	Select Static.
Private IP address	Enter 10.1.0.6.

Select Create.
Start the virtual machine.
Repeat steps 1 through 16 for myVM2, replacing the following information:

Setting myVM2

Name myVM2NIC2

Private IP address 10.1.0.7

Setting	myVM2
Name	myVM2NIC2
Private IP address	10.1.0.7

Configure virtual machines

You connect to myVM1 and myVM2 with Azure Bastion and configure the secondary network configuration in this section. You add a route for the gateway for the secondary network configuration. Then you install IIS on each virtual machine and customize the websites to display the hostname of the virtual machine.

In the search box at the top of the portal, enter Virtual machine. Select Virtual machines in the search results.
Select myVM1.
Start myVM1.
In Overview, select Connect then Bastion.
Enter the username and password you entered when you created the virtual machine.
Select Allow for Bastion to use the clipboard.
On the server desktop, navigate to Start > Windows Administrative Tools > Windows PowerShell > Windows PowerShell.

In the PowerShell window, execute the route print command, which returns output similar to the following output for a virtual machine with two attached network interfaces:

===========================================================================
Interface List
  4...60 45 bd 9c c7 00 ......Microsoft Hyper-V Network Adapter
 11...60 45 bd 8d 44 fa ......Microsoft Hyper-V Network Adapter #3
  1...........................Software Loopback Interface 1
===========================================================================

IPv4 Route Table
===========================================================================
Active Routes:
Network Destination        Netmask          Gateway       Interface  Metric
          0.0.0.0          0.0.0.0         10.1.0.1         10.1.0.4     10
         10.1.0.0    255.255.255.0         On-link          10.1.0.4    266
         10.1.0.0    255.255.255.0         On-link          10.1.0.6    266
         10.1.0.4  255.255.255.255         On-link          10.1.0.4    266
         10.1.0.6  255.255.255.255         On-link          10.1.0.6    266
       10.1.0.255  255.255.255.255         On-link          10.1.0.4    266
       10.1.0.255  255.255.255.255         On-link          10.1.0.6    266
        127.0.0.0        255.0.0.0         On-link         127.0.0.1    331
        127.0.0.1  255.255.255.255         On-link         127.0.0.1    331
  127.255.255.255  255.255.255.255         On-link         127.0.0.1    331
    168.63.129.16  255.255.255.255         10.1.0.1         10.1.0.4     11
  169.254.169.254  255.255.255.255         10.1.0.1         10.1.0.4     11
        224.0.0.0        240.0.0.0         On-link         127.0.0.1    331
        224.0.0.0        240.0.0.0         On-link          10.1.0.4    266
        224.0.0.0        240.0.0.0         On-link          10.1.0.6    266
  255.255.255.255  255.255.255.255         On-link         127.0.0.1    331
  255.255.255.255  255.255.255.255         On-link          10.1.0.4    266
  255.255.255.255  255.255.255.255         On-link          10.1.0.6    266
===========================================================================
Persistent Routes:
  None

IPv6 Route Table
===========================================================================
Active Routes:
 If Metric Network Destination      Gateway
  1    331 ::1/128                  On-link
  4    266 fe80::/64                On-link
 11    266 fe80::/64                On-link
 11    266 fe80::382:8783:5d2:f71e/128       
                                    On-link
  4    266 fe80::1575:ced8:3e94:f23a/128
                                    On-link
  1    331 ff00::/8                 On-link
  4    266 ff00::/8                 On-link
 11    266 ff00::/8                 On-link
===========================================================================
Persistent Routes:
  None

In this example, Microsoft Hyper-V Network Adapter #3 (interface 13) is the secondary network interface that doesn't have a default gateway assigned to it.

In the PowerShell window, execute the ipconfig /all command to see which IP address is assigned to the secondary network interface. In this example, 10.1.0.6 is assigned to interface 13. No default gateway address is returned for the secondary network interface.


   Connection-specific DNS Suffix  . : pbu0t5vjr3sevaritkncspakhd.ax.internal.chinacloudapp.cn
   Description . . . . . . . . . . . : Microsoft Hyper-V Network Adapter #3
   Physical Address. . . . . . . . . : 60-45-BD-A1-75-FB
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::dfb3:b93e:3516:c5b6%12(Preferred)
   IPv4 Address. . . . . . . . . . . : 10.1.0.6(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : Monday, December 12, 2022 7:42:31 PM
   Lease Expires . . . . . . . . . . : Friday, January 19, 2159 2:17:19 AM
   Default Gateway . . . . . . . . . :
   DHCP Server . . . . . . . . . . . : 168.63.129.16
   DHCPv6 IAID . . . . . . . . . . . : 207635901
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-2B-28-C9-C0-60-45-BD-9B-ED-AE
   DNS Servers . . . . . . . . . . . : 168.63.129.16
   NetBIOS over Tcpip. . . . . . . . : Enabled

To route all traffic for addresses outside the subnet to the gateway, execute the following command:
```
route -p add 0.0.0.0 MASK 0.0.0.0 10.1.0.1 METRIC 5015 IF 13
```
In this example, 10.1.0.1 is the default gateway for the virtual network you created previously.

Execute the following commands or copy and paste the code into the PowerShell window to install and configure IIS and the test websites:

## Install IIS and the management tools. ##
Install-WindowsFeature -Name Web-Server -IncludeManagementTools

## Set the binding for the Default website to 10.1.0.4:80. ##
$para1 = @{
    Name = 'Default Web Site'
    BindingInformation = '10.1.0.4:80:'
    Protocol = 'http'
}
New-IISSiteBinding @para1

## Remove the default site binding. ##
$para2 = @{
    Name = 'Default Web Site'
    BindingInformation = '*:80:'
}
Remove-IISSiteBinding @para2

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

## Add a new htm file that displays the Contoso website. ##
$para3 = @{
    Path = 'c:\inetpub\wwwroot\iisstart.htm'
    Value = $("Hello World from www.contoso.com" + "-" + $env:computername)
}
Add-Content @para3

## Create folder to host website. ##
$para4 = @{
    Path = 'c:\inetpub\'
    Name = 'fabrikam'
    Type = 'directory'
}
New-Item @para4

 ## Create a new website and site binding for the second IP address 10.1.0.6. ##
$para5 = @{
    Name = 'Fabrikam'
    PhysicalPath = 'c:\inetpub\fabrikam'
    BindingInformation = '10.1.0.6:80:'
}
New-IISSite @para5

## Add a new htm file that displays the Fabrikam website. ##
$para6 = @{
    Path = 'C:\inetpub\fabrikam\iisstart.htm'
    Value = $("Hello World from www.fabrikam.com" + "-" + $env:computername)

}
Add-Content @para6

Close the Bastion connection to myVM1.

Repeat steps 1 through 12 for myVM2. Use the following PowerShell code for myVM2 for the IIS install.

## Install IIS and the management tools. ##
Install-WindowsFeature -Name Web-Server -IncludeManagementTools

## Set the binding for the Default website to 10.1.0.5:80. ##
$para1 = @{
    Name = 'Default Web Site'
    BindingInformation = '10.1.0.5:80:'
    Protocol = 'http'
}
New-IISSiteBinding @para1

## Remove the default site binding. ##
$para2 = @{
    Name = 'Default Web Site'
    BindingInformation = '*:80:'
}
Remove-IISSiteBinding @para2

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

## Add a new htm file that displays the Contoso website. ##
$para3 = @{
    Path = 'c:\inetpub\wwwroot\iisstart.htm'
    Value = $("Hello World from www.contoso.com" + "-" + $env:computername)
}
Add-Content @para3

## Create folder to host website. ##
$para4 = @{
    Path = 'c:\inetpub\'
    Name = 'fabrikam'
    Type = 'directory'
}
New-Item @para4

## Create a new website and site binding for the second IP address 10.1.0.7. ##
$para5 = @{
    Name = 'Fabrikam'
    PhysicalPath = 'c:\inetpub\fabrikam'
    BindingInformation = '10.1.0.7:80:'
}
New-IISSite @para5

## Add a new htm file that displays the Fabrikam website. ##
$para6 = @{
    Path = 'C:\inetpub\fabrikam\iisstart.htm'
    Value = $("Hello World from www.fabrikam.com" + "-" + $env:computername)
}
Add-Content @para6

Create load balancer

You create a zone redundant load balancer that load balances virtual machines in this section.

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:

Two frontend IP addresses, one for each website.
Backend pools
Inbound load-balancing rules

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 myLoadBalancer
Region	Select China North 3.
SKU	Leave the default Standard.
Type	Select Public.
Tier	Leave the default Regional.

Select Next: Frontend IP configuration.
In Frontend IP configuration, select + Add a frontend IP configuration.

Enter or select the following information in Add frontend IP configuration:

Setting	Value
Name	Enter Frontend-contoso.
IP version	Select IPv4.
IP type	Select IP address.
Public IP address	Select Create new. Enter myPublicIP-contoso for Name Select Zone-redundant in Availability zone. Select OK.

Note

For more information on IP prefixes, see Azure Public IP prefix.

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 Add.
Select + Add a frontend IP configuration.

Enter or select the following information in Add frontend IP configuration:

Setting	Value
Name	Enter Frontend-fabrikam.
IP version	Select IPv4.
IP type	Select IP address.
Public IP address	Select Create new. Enter myPublicIP-fabrikam for Name Select Zone-redundant in Availability zone. Select OK.

Select Add.
Select Next: Backend pools.
In the Backend pools tab, select + Add a backend pool.
Enter or select the following information in Add a backend pool:

Setting Value

Name Enter myBackendPool-contoso.

Virtual network Select myVNet.

Backend Pool Configuration Select NIC.
In IP configurations, select + Add.
Select myVM1 and myVM2 that correspond with ipconfig1 (10.1.0.4) and ipconfig1 (10.1.0.5).
Select Add.
Select Save.
Select + Add a backend pool.
Enter or select the following information in Add a backend pool:

Setting Value

Name Enter myBackendPool-fabrikam.

Virtual network Select myVNet.

Backend Pool Configuration Select NIC.
In IP configurations, select + Add.
Select myVM1 and myVM2 that correspond with ipconfig1 (10.1.0.6) and ipconfig1 (10.1.0.7).
Select Add.
Select Save.
Select Next: Inbound rules.
In Load balancing rule in the Inbound rules tab, select + Add a load balancing rule.

Setting	Value
Name	Enter myBackendPool-contoso.
Virtual network	Select myVNet.
Backend Pool Configuration	Select NIC.

Setting	Value
Name	Enter myBackendPool-fabrikam.
Virtual network	Select myVNet.
Backend Pool Configuration	Select NIC.

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

Setting	Value
Name	Enter myHTTPRule-contoso
IP Version	Select IPv4.
Frontend IP address	Select Frontend-contoso.
Backend pool	Select myBackendPool-contoso.
Protocol	Select TCP.
Port	Enter 80.
Backend port	Enter 80.
Health probe	Select Create new. In Name, enter myHealthProbe-contoso. Select TCP in Protocol. Leave the rest of the defaults, and select OK.
Session persistence	Select None.
Idle timeout (minutes)	Enter or select 15.
TCP reset	Select Enabled.
Floating IP	Select Disabled.
Outbound source network address translation (SNAT)	Leave the default of (Recommended) Use outbound rules to provide backend pool members access to the internet.

Select Add.
Select Add a load balancing rule.

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

Setting	Value
Name	Enter myHTTPRule-fabrikam
IP Version	Select IPv4.
Frontend IP address	Select Frontend-fabrikam.
Backend pool	Select myBackendPool-fabrikam.
Protocol	Select TCP.
Port	Enter 80.
Backend port	Enter 80.
Health probe	Select Create new. In Name, enter myHealthProbe-fabrikam. Select TCP in Protocol. Leave the rest of the defaults, and select OK.
Session persistence	Select None.
Idle timeout (minutes)	Enter or select 15.
TCP reset	Select Enabled.
Floating IP	Select Disabled.
Outbound source network address translation (SNAT)	Leave the default of (Recommended) Use outbound rules to provide backend pool members access to the internet.

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

Note

In this example we created a NAT gateway to provide outbound Internet access. The outbound rules tab in the configuration is bypassed as it's optional 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

Test load balancer

In this section, you discover the public IP address for each website. You enter the IP into a browser to test the websites you created earlier.

In the search box at the top of the portal, enter Public IP. Select Public IP addresses in the search results.
Select myPublicIP-contoso.
Copy the IP address in the overview page of myPublicIP-contoso.
Open a web browser and paste the public IP address into the address bar.
Return to Public IP addresses. Select myPublicIP-fabrikam.
Copy the IP address in the overview page of myPublicIP-fabrikam.
Open a web browser and paste the public IP address into the address bar.
To test the load balancer, refresh the browser or shut down one of the virtual machines.

Clean up resources

If you're not going to continue to use this application, delete the virtual machines and load balancer with the following steps:

In the search box at the top of the portal, enter Resource group. Select Resource groups in the search results.
Select load-balancer-rg in Resource groups.
Select Delete resource group.
Enter load-balancer-rg in TYPE THE RESOURCE GROUP NAME:. Select Delete.