Network Load Balancer (NLB) in AWS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Network Load Balancer (NLB) in AWS?

An NLB is a type of load balancer that distributes incoming network traffic across multiple targets at the transport layer (Layer 4). It is designed to handle millions of requests per second while maintaining ultra-low latency.

intermediate

How does an NLB differ from an Application Load Balancer (ALB)?

NLB works at Layer 4 (transport layer) and routes connections based on IP protocol data. ALB works at Layer 7 (application layer) and routes based on HTTP/HTTPS content. NLB is better for TCP/UDP traffic and extreme performance needs.

beginner

What is a key benefit of using an NLB for TCP traffic?

NLB can handle sudden and volatile traffic patterns while maintaining high throughput and low latency, making it ideal for TCP and UDP traffic that requires fast, reliable connections.

intermediate

Explain the concept of 'static IP' in the context of NLB.

NLB provides a static IP per Availability Zone, which means the IP addresses do not change. This helps clients whitelist IPs and simplifies firewall rules.

beginner

What is the role of target groups in NLB?

Target groups are collections of endpoints (like EC2 instances or IP addresses) that receive traffic from the NLB. They help organize and manage where the load balancer sends requests.

At which OSI layer does a Network Load Balancer operate?

A Layer 3 (Network Layer)

B Layer 4 (Transport Layer)

C Layer 7 (Application Layer)

D Layer 2 (Data Link Layer)

NLB operates at Layer 4, handling TCP/UDP traffic based on transport layer information.

Which type of traffic is best suited for an NLB?

A TCP and UDP traffic requiring high performance

B HTTP/HTTPS traffic with content-based routing

C Static website hosting

D Email delivery

NLB is optimized for TCP and UDP traffic with high throughput and low latency.

What is a key advantage of NLB's static IP addresses?

A They change frequently for security

B They enable content-based routing

C They allow clients to whitelist IPs easily

D They reduce DNS lookup times

Static IPs help clients set firewall rules by whitelisting known IP addresses.

How does NLB handle sudden spikes in traffic?

A It queues requests until capacity is available

B It redirects traffic to a backup server

C It drops excess requests

D It automatically scales to handle millions of requests per second

NLB is designed to scale automatically and handle sudden traffic spikes efficiently.

What is the purpose of target groups in NLB?

A To group endpoints that receive traffic from the NLB

B To store user session data

C To encrypt network traffic

D To monitor network latency

Target groups organize the endpoints (like EC2 instances) that the NLB routes traffic to.

Describe how a Network Load Balancer manages incoming traffic and what makes it suitable for high-performance applications.

Think about speed, traffic type, and IP stability.

Explain the difference between Network Load Balancer and Application Load Balancer and when to use each.

Focus on OSI layers and traffic types.