Load balancing rules in Azure - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ service_behavior

intermediate

Understanding Azure Load Balancer Rule Behavior

You have an Azure Load Balancer with a rule that forwards TCP traffic from port 80 on the frontend to port 8080 on backend VMs. What happens when a client sends a TCP request to port 80?

A The Load Balancer forwards the request to port 8080 on one of the backend VMs selected by the load balancing algorithm.

B The Load Balancer forwards the request to port 80 on the backend VMs without changing the port.

C The Load Balancer rejects the request because frontend and backend ports must be the same.

D The Load Balancer forwards the request to port 8080 on the client machine.

💡 Hint

Think about how the load balancing rule maps frontend ports to backend ports.

The load balancing rule maps incoming traffic on the frontend port to a specified backend port. Here, port 80 on the frontend is mapped to port 8080 on backend VMs, so traffic is forwarded accordingly.

❓ Configuration

intermediate

Configuring a Load Balancing Rule with Session Persistence

You want to configure an Azure Load Balancer rule to keep client sessions sticky based on the client's IP address. Which setting should you enable in the load balancing rule?

A Set the session persistence to 'Client IP'.

B Set the session persistence to 'Source IP affinity'.

C Set the session persistence to 'Client IP and protocol'.

D Set the session persistence to 'None'.

💡 Hint

Session persistence keeps traffic from the same client going to the same backend VM.

Setting session persistence to 'Client IP' ensures that all requests from the same client IP address are directed to the same backend VM, maintaining session stickiness.

❓ Architecture

advanced

Designing a Load Balancer for High Availability with Multiple Frontend IPs

You need to design an Azure Load Balancer that supports two different public IP addresses for different services but shares the same backend pool. How should you configure the load balancing rules?

A Assign both frontend IPs to a single backend VM without load balancing rules.

B Create one load balancing rule with both frontend IPs assigned to it.

C Create two backend pools, each with its own load balancing rule and frontend IP.

D Create two load balancing rules, each with a different frontend IP configuration but pointing to the same backend pool.

💡 Hint

Each load balancing rule must have one frontend IP configuration.

Each load balancing rule is associated with one frontend IP configuration and one backend pool. To support multiple frontend IPs for different services sharing the same backend pool, create separate rules for each frontend IP.

❓ security

advanced

Securing Load Balancer Rules with Network Security Groups

You have an Azure Load Balancer rule that forwards traffic on port 443 to backend VMs. To ensure only HTTPS traffic is allowed, what must you configure in the Network Security Group (NSG)?

A Allow all inbound traffic to the backend VMs regardless of port.

B Allow inbound traffic on port 443 to the Load Balancer's frontend IP and deny other ports.

C Allow inbound traffic on port 443 directly to backend VMs and deny other ports.

D Deny all inbound traffic to the Load Balancer's frontend IP.

💡 Hint

NSGs control traffic at the network interface or subnet level.

The NSG associated with the backend VMs should allow inbound traffic on port 443 and deny other ports. This ensures only HTTPS traffic reaches the backend VMs, as the Load Balancer forwards traffic to this port.

✅ Best Practice

expert

Optimizing Load Balancer Rules for Backend Health Probes

You want to ensure your Azure Load Balancer only sends traffic to healthy backend VMs. Which configuration is required in the load balancing rule and health probe setup?

A Configure the load balancing rule without a health probe; the Load Balancer automatically detects unhealthy VMs.

B Associate a health probe with the load balancing rule and configure the probe to check the backend VMs' health on a specific port.

C Use a health probe but do not associate it with the load balancing rule; it will still monitor backend health.

D Configure the health probe to check the frontend IP instead of backend VMs.

💡 Hint

Health probes must be linked to load balancing rules to affect traffic distribution.

Health probes monitor backend VM health on a specified port. Associating the probe with the load balancing rule ensures traffic is only sent to healthy VMs.