Real-world Scenarios: Troubleshooting Azure Deployments for AZ-104

This blog discusses some real-world scenarios of troubleshooting Azure deployments for AZ-104 and the diagnostic requirements for network connectivity and load balancing. The AZ-104 Microsoft Azure Administrator certificate validates the skills and knowledge required for effectively managing and maintaining Azure environments. To maintain a cloud environment, you must ensure the smooth operation of cloud services and resources. When issues arise such as performance problems, connectivity failures, or misconfigurations—you must diagnose and resolve them quickly to minimize downtime and service disruptions.

Network Connectivity and Load Balancing Troubleshooting as Focus Areas

The Microsoft Azure Administrator AZ-104 exam emphasizes load balancing and Virtual Network (VNet)-related issues in the context of Azure deployment issues and solutions. The exam guide has two troubleshooting sections: “troubleshoot network connectivity” and “troubleshoot load balancing” as subtopics under the Implement and manage virtual networking topic.

Network connectivity and load-balancing features are fundamental to ensuring the overall functionality and performance of cloud infrastructure. These two components complement each other by ensuring efficient traffic distribution and secure connectivity in Azure environments.

They are crucial for Azure administrators because they directly impact the availability, performance, and security of cloud-based applications and services.

The following figure illustrates a load-balanced pool of computing resources in a single VNet and subnet.

In the AZ-104 exam, you’ll be tested on practical scenarios where you need to:

• Diagnose and resolve load balancing- and network connectivity-related problems.
• Implement best practices for load balancing and network configurations.
• Ensure proper integration and communication between load balancers and network resources such as virtual machines (VMs).

Role of Load Balancers in Azure Deployments

Load balancing refers to the distribution of incoming network traffic across multiple resources, such as VMs, services, or servers to ensure no single server becomes overwhelmed. A load balancer is a device that distributes traffic coming into multiple servers. Load balancers help maintain application performance and high availability even if individual servers or VMs fail.

Azure provides multiple load-balancing services, each suited for different scenarios. However, the AZ-104 exam mostly focuses on the following two:

• Azure Load Balancer (Basic and Standard SKU covered in this exam): It is an OSI layer 4 load balancer that works with TCP/UDP protocols and distributes internal and external traffic to Azure VM. Load Balancers are of two types:

⇒ Public Load Balancer: provides outbound connections for virtual VMs inside your virtual network (VNet).

⇒ Internal Load Balancer: balances traffic within a VNet.

• Azure Application Gateway: It is an OSI layer 7 load balancer that helps manage traffic to VMs for web applications. It can route traffic based on HTTP(S) requests and application content, such as URL paths or headers. Some of its important features are SSL termination and Web Application Firewall (WAF).

Key Troubleshooting Areas of Azure Load Balancer

As an Azure administrator, understanding the key troubleshooting areas and tasks of Azure Load Balancer is crucial for a successful deployment. Here are some of the common issues:

Before diving deeper into more complex troubleshooting diagnostics, an ideal first step in the Azure Load Balancer troubleshooting process check the various options under Settings in your load balancer. The following table describes these options and the example diagnostic question.

Role of Virtual Networks in Azure Deployment

Azure Virtual Network (VNet) is a service for creating a logical representation of the network for running VMs and applications in the cloud. By providing an isolated environment, VNets ensure that Azure services, virtual machines, and other resources can communicate with each other securely and efficiently. Within a VNet, load balancers distribute incoming network traffic across multiple instances of an application or servic to ensure high availability and fault tolerance.

Key VNets Troubleshooting Areas

Here are some common troubleshooting areas for VNets.

Azure Network Watcher and Azure Monitor as Diagnostic Services

Network Watcher is an Azure service that provides monitoring, diagnostics, and deep insights into the health, performance, and security of your network infrastructure.

Azure Monitor is a dashboard for all Azure services. The Networks feature provides network performance metrics.

Network Watcher and Azure Monitor complement each other. While the former provides detailed network diagnostics, the latter serves as the platform that stores, analyzes, and visualizes this data, enabling more effective troubleshooting and monitoring of network issues. Both work together to provide comprehensive network diagnostics, monitoring, and troubleshooting.

Here are some troubleshooting examples using Network Watcher diagnostic and monitoring tools for network connectivity issues.

Scenario 1: Intermittent Connectivity Issues While Accessing Application

A web application is deployed on a set of VMs behind an Azure Load Balancer. The application is configured to handle both HTTP and HTTPS traffic using different load-balancing rules. Users report intermittent connectivity issues. Some users cannot access the application at all, while others experience slow or dropped connections.

Troubleshooting

The administrator navigates to Azure portal > Load Balancer > Settings > Load Balancing Rules. The settings show that only some VMs are included in the backend pool excluding other VMs that should be handling traffic.

Resolution

The administrator updates the Backend Pool configuration to include all healthy VMs that are part of the web application deployment. This ensures the traffic is distributed across all VMs, improving performance and availability.

Scenario 2: Azure VMs Unable to Connect Within the Same Virtual Network

Azure VMs are deployed in the same virtual network and subnet, but they are unable to communicate with each other. Ping requests and RDP/SSH connections fail, despite both VMs having correct IP addresses and no apparent firewall restrictions.

Troubleshooting

• The administrator navigates to Azure Network Watcher and uses the IP Flow Verify tool.

• The administrator enters the source and destination IP addresses of the VMs, along with the specific port and protocol (TCP for RDP or SSH).

• IP Flow Verify reports that the traffic is being denied due to a Network Security Group (NSG) rule.

• Upon reviewing the NSG, the administrator finds an incorrectly configured inbound security rule blocking communication between the VMs.

Note: An NSG is part of the virtual network in a resource group and contains rules that control the incoming and outgoing traffic to and from the VM.

Resolution

The administrator updates the NSG rule to allow traffic on the appropriate ports. After verifying the changes, the VMs can communicate successfully. To update the NSG rule, the administrator follows these steps:

1. Navigate to Azure portal > Network Security Groups.
2. Select the relevant NSG.
3. Update Inbound/Outbound Security Rules.
4. Save changes.

After this update, the VMs can communicate successfully.

Conclusion

Effective Troubleshooting of Azure deployments for AZ-104 in real-world scenarios requires a thorough understanding of key areas such as load balancing and VNet configurations. By leveraging diagnostic tools and methods, administrators can swiftly identify and resolve issues. And to develop strong troubleshooting skills, you need ample lad practice. Hands-on experience in a controlled environment helps you develop familiarity with tools and techniques, understand system interactions, and refine problem-solving abilities. To learn more, sign up for the Whizlabs Exam AZ-104: Microsoft Azure Administrator course. For additional hands-on experience of the services, check our AWS hands-on labs and AWS sandboxes.