External and internal load balancers

- [Narrator] Now, let's take a look at the differences … between External Load Balancers and Internal Load Balancers. … I'm going to use each one. … An External Load Balancer basically maps a public IP address … and ports to internal targets. … That means that it will receive communications … from the different clients that are on the internet, … and send those requests to internal targets … like a web server, or a scale set. … It applies load balancing rules. … So when the load balancer receives the request, … it will then decide which of the servers … in the back-end pool will receive those requests. … It also uses Port Address Translation … which lets the load balancer modify the port … where the client is connecting. … So on the external side … where the load balancer has the public IP address, … it could be receiving connections to the Port 80 … but then those connections could be re-sent … to the Port 8080 on the back-end. … And this is typically used for websites … and similar services. …