Classic Load Balancer (ELB) vs Application Load Balancer (ALB)
Understanding the Classic Load Balancer:
- The AWS Classic Load Balancer (CLB) operates at Layer 4 of the OSI model. What this means is that the load balancer routes traffic between clients and backend servers based on IP address and TCP port.
- For example, an ELB at a given IP address receives a request from a client on TCP port 80 (HTTP). It will then route that request based on the rules previously configured when setting up the load balancer to a specified port on one of a pool of backend servers
Understanding the Application Load Balancer:
- AWS Application Load Balancer (ALB) operates at Layer 7 of the OSI model. At Layer 7, the ELB has the ability to inspect application-level content, not just IP and port. This lets it route based on more complex rules than with the Classic Load…
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