Network load balancer real life examples?

Question

Even after a lot of googling, I could not find a simple answer to this question. All I could find was it's layer 4 load balancer that can handle millions of requests per second, and support for static/elastic ip. Could someone please give me an example where network load balancers are used in real life? A simple use case. When to pick network load balancer over application load balancer?

Answer 1

When compared to an Application Load Balancer a simple explanation goes like this: Network Load Balancer is used anywhere where the application behind the balancer doesn't work over HTTP(S), but uses some other protocol. Including, but not limited to:

• Legacy applications that implement custom protocol.
• NTP servers.
• SMTP server.
• Database servers.
• MQTT brokers.
• High performance queue servers (ActiveMQ, RabbitMQ, ZeroMQ etc.).
• Message processing applications (think Kafka and Co.).

Answer 2

I would like to complement @Sergey list with few more scenarios where NLB is useful:

• NLB provides static IP address, ALB does not. So use it when you require a static IP for your LB. Similarly, it is the only balancer that can use Elastic IP addresses.

• Use NLB when you require end-to-end SSL encryption. ALB will always terminate SSL connection, which may be not desired due to strict security requirements.

• NLB is the only balancer type that can be used for API Gateway VpcLink or VPC PrivateLink technologies.

• NLB does not have Security Groups.