Examkin

Question

Difficulty: MediumApplication Load Balancing and Delivery

An enterprise is designing a high-availability infrastructure for a custom TCP-based application running on Azure Virtual Machines (VMs) in the West US 3 region. The VMs are currently configured with Basic SKU Public IP addresses. To meet SLA requirements, the load balancing solution must support Availability Zones. You plan to implement an Azure Load Balancer to distribute the incoming TCP traffic. Which of the following actions is required to design a valid load balancing configuration that supports Availability Zones?

  1. A
    Deploy a Standard Load Balancer and associate the existing Basic SKU Public IP addresses of the virtual machines with the backend pool.
  2. B
    Deploy a Basic Load Balancer and configure a zone-redundant frontend IP configuration.
  3. Deploy a Standard Load Balancer and upgrade the Public IP addresses of the virtual machines to Standard SKU.Answer
  4. D
    Deploy an Azure Application Gateway v2 and configure it to route the TCP traffic using Basic SKU frontend IP addresses.

Answer

Deploy a Standard Load Balancer and upgrade the Public IP addresses of the virtual machines to Standard SKU.
Deploying a Standard Load Balancer and upgrading the virtual machines' Public IP addresses to Standard SKU is the correct design. The Standard Load Balancer is required to utilize Availability Zones for high availability. In addition, Azure requires all network resources attached to a Standard Load Balancer backend pool to be of the Standard SKU, meaning the existing Basic SKU Public IPs on the VMs must be upgraded to Standard SKU to pass validation.

Step-by-Step Solution

1
Analyze the load balancing protocol and high-availability requirements.
The application requires Layer 4 TCP load balancing with support for Availability Zones.
This rules out HTTP-only load balancers like Application Gateway and restricts the selection to Azure Load Balancer SKUs that support Availability Zones.
2
Determine the appropriate Azure Load Balancer SKU based on zone support.
Azure Standard Load Balancer must be used.
Basic Load Balancer does not support Availability Zones, meaning only the Standard SKU can meet the zone-redundancy requirements.
3
Check compatibility between the backend virtual machines and the selected Load Balancer SKU.
The Basic SKU Public IPs on the virtual machines must be upgraded to Standard SKU.
Standard Load Balancer requires all backend resources to use Standard SKU IP configurations. Mixing Basic and Standard SKUs in the backend pool of a Standard Load Balancer causes validation failures.

Key Concept

SKU alignment and backend resource compatibility constraints in Azure Load Balancer designs
Rate this question

Topics

Application Load Balancing and Delivery

More questions from this topic