Azure Networking Cookbook

Creating inbound Network Address Translation (NAT) rules

Inbound NAT rules are an optional setting in the Azure load balancer. These rules essentially create another port mapping from frontend to backend, forwarding traffic over a specific port on the frontend to a specific port in the backend. The difference between inbound NAT rules and port mapping in load balancer rules is that inbound NAT rules apply to direct forwarding to a VM, whereas load balancer rules forward traffic to a backend pool.