Implementing Azure Load Balancer for traffic distribution

Posted on by Panther

Introduction

When it comes to distributing traffic across services, load balancing is an essential component. With Azure Load Balancer, you can distribute traffic to multiple servers, providing high availability, scalability, and excellent performance. The Azure Load Balancer is a Layer-4 (Transport Layer) load balancer that works with different protocols such as TCP, UDP, and HTTP/HTTPS.

In this tutorial, we will learn how to implement Azure Load Balancer for traffic distribution and provide high availability for our services.

Prerequisites

Before we get started, there are a few things we need to have in place. These include:

  1. An Azure subscription
  2. Two or more virtual machines (VMs) running in Azure. These VMs should be set up and running with their respective services.
  3. An Azure Virtual Network (VNet) configured so that the VMs are connected to it.
  4. Access to the Azure Portal.

Step 1: Create an Azure Load Balancer

The first step is to create an Azure Load Balancer. We can do this by following these steps:

  1. Open the Azure Portal and navigate to the Load Balancer page by searching for “Load Balancer” in the search bar.

  2. Click on the “+ Add” button to add a new Load Balancer.

  3. In the “Basic” tab, enter a name for the Load Balancer, select the appropriate subscription, and resource group.

  4. Choose the appropriate region for the Load Balancer and select “Public” IP Address assignment.

  5. In the “Backend Pools” tab, click on the “+ Add” button to create a new pool.

  6. Enter a name for the pool and select the appropriate VM from the list of available VMs. Repeat this step to add all the VMs that require load balancing.

  7. In the “Health probes” tab, click on the “+ Add” button to create a new health probe. Enter the required details such as the protocol, port, and frequency.

  8. In the “Load balancing rules” tab, click on the “+ Add” button to create a new load balancing rule. Enter a name for the rule, select the protocol (TCP/UDP/HTTP), select the frontend IP address (Public IP), backend pool, and health probe.

  9. Click on the “Review + Create” button to create the Load Balancer.

Step 2: Test Azure Load Balancer

Once the Load Balancer is created, we can test it by accessing the services running on the VMs. To do this, we can follow the steps below:

  1. Open the Azure Portal and navigate to the Load Balancer page.

  2. Select the Load Balancer that we just created.

  3. In the “Overview” tab, copy the Public IP address.

  4. Open a web browser and paste the Public IP address, followed by the port number (if applicable). For example, http://:80

  5. The Load Balancer should distribute the traffic evenly across the VMs, and the service should be accessible.

Step 3: Configure Load Balancer for NAT Rules

Sometimes, services require static IP addresses when they communicate with external systems. In such cases, we can configure our Load Balancer to use NAT rules. With NAT, the Load Balancer replaces the source IP address of outgoing traffic from the VMs with a static IP address.

To do this, we can follow these steps:

  1. Open the Azure Portal and navigate to the Load Balancer page.

  2. Select the Load Balancer that we just created.

  3. In the “Backend Pools” tab, click on the name of the pool that we want to configure NAT rules for.

  4. In the “Inbound NAT Rules” tab, click on the “+ Add” button to create a new NAT rule.

  5. Enter a name for the NAT rule, select the public IP address that we want to use for NAT, select the protocol, enter the port number, and select the backend port that the traffic should be redirected to.

  6. Click on the “Create” button to create the NAT rule.

Step 4: Configure Load Balancer to use a Custom Domain Name

By default, the Load Balancer uses a generic DNS name that Azure provides. This name is not suitable for production environments. We can configure the Load Balancer to use a custom domain name that we own. To do this, we can follow these steps:

  1. Open the Azure Portal and navigate to the Load Balancer page.

  2. Select the Load Balancer that we just created.

  3. In the “Frontend IP Configuration” tab, click on the name of the IP configuration that has the public IP address that we want to use.

  4. In the configuration page, select the “Custom Domain Name” tab.

  5. Enter the custom domain name that we want to use and click on the “Create” button.

  6. Once the DNS records are created, the custom domain name will be visible in the Overview tab.

Conclusion

In this tutorial, we learned how to implement Azure Load Balancer for traffic distribution and provide high availability for our services. We also learned how to configure Load Balancer for NAT rules and how to use a custom domain name. With Azure Load Balancer, we can ensure that our services are always available, provide excellent performance, and are scalable.

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