AWS — Elastic Load Balancer (ELB) Overview
Introduction to AWS Elastic Load Balancer — What is ELB?
TL;DR
AWS Elastic Load Balancer (ELB) automatically distributes your incoming traffic across multiple targets, such as EC2 instances, containers, and IP addresses, in one or more Availability Zones. It monitors the health of its registered targets, and routes traffic only to the healthy targets. Elastic Load Balancing scales your load balancer as your incoming traffic changes over time. It can automatically scale to the vast majority of workloads.
ELB Types
- Application Load Balancer (ALB)
- Network Load Balancer (NLB)
- Gateway Load Balancer (GWLB)
- Classic Load Balancer (CLB)
Difference between Application load balancer and Network load balancer
ELB Schemes
- Internet-facing: ELB nodes have public IP addresses.
- Internal: ELB nodes have private IP addresses.
Both internet-facing and internal load balancers route requests to your targets using private IP addresses. Therefore, your targets do not need public IP addresses to receive requests from an internal or an internet-facing load balancer.
