AWS Mastery for .NET Architects
Lesson 14 of 30 47% of course

Application Load Balancer (ALB) vs Network Load Balancer (NLB)

16 · 8 min · 5/23/2026

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Scaling Connections

Elastic Load Balancing (ELB) is the gateway to your server fleet. Choosing between ALB and NLB depends on your protocol needs.

1. Application Load Balancer (ALB) - Layer 7

Operates at the HTTP/HTTPS level. It can 'Read' the request and route based on Path (/api vs /web) or Hostname. Use this for 99% of web applications and REST APIs.

2. Network Load Balancer (NLB) - Layer 4

Operates at the TCP/UDP level. It is extremely fast and handles millions of requests per second with ultra-low latency. Use this for **gRPC**, Games, or any high-performance non-HTTP traffic.

3. Architect Insight

Q: "Should I terminate SSL at the Load Balancer or the Instance?"

Architect Answer: "Terminate at the **Load Balancer**. This is called **SSL Offloading**. It frees up your .NET app's CPU from the heavy math of encryption/decryption. AWS also provides free SSL certificates via **ACM (Certificate Manager)** if you terminate at the LB. It's a win-win for security and performance."

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AWS Mastery for .NET Architects

On this page

1. Application Load Balancer (ALB) - Layer 7 2. Network Load Balancer (NLB) - Layer 4 3. Architect Insight
1. AWS Global Infrastructure
AWS Foundations: Regions, Availability Zones, and Edge Locations VPC Deep Dive: Subnets, Route Tables, and Internet Gateways IAM (Identity and Access Management): The Principle of Least Privilege Security Groups vs Network ACLs: Handling traffic for .NET apps
2. Compute for .NET
EC2 (Elastic Compute Cloud): Choosing the right instance for C# apps AWS Lambda: Serverless .NET with Native AOT ECS & Fargate: Containerizing .NET APIs at scale Auto Scaling Groups: Handling spikes in traffic
3. Storage & Databases
S3 (Simple Storage Service): Architecting a binary storage layer RDS (Relational Database Service): Managed SQL Server in the cloud DynamoDB Mastery: NoSQL for extreme scale ElastiCache: Boosting performance with Redis/Memcached
4. Networking & Content Delivery
Route 53: DNS management and health checks Application Load Balancer (ALB) vs Network Load Balancer (NLB) CloudFront: Accelerating frontend delivery via CDN API Gateway: Building a unified entry point for Microservices
5. Security & Compliance
AWS WAF: Protecting your APIs from common web attacks AWS Secrets Manager: Managing connection strings securely KMS (Key Management Service): Data encryption for .NET CloudTrail: Auditing your infrastructure changes
6. Messaging & Events
SQS (Simple Queue Service): Decoupling .NET services SNS (Simple Notification Service): Pub/Sub patterns in AWS EventBridge: Building an event-driven bus Step Functions: Orchestrating complex serverless workflows
7. Monitoring & DevOps
CloudWatch: Metrics, Logs, and Alarms for C# apps X-Ray: Distributed tracing for .NET Microservices AWS CodePipeline: CI/CD for .NET on AWS CloudFormation & CDK: Infrastructure as Code (IaC) with C#
8. Optimization & Scale
Cost Optimization (FinOps): Reducing your monthly AWS bill Case Study: Migrating a legacy Monolith to a Cloud-Native AWS stack