All outbound traffic to the Internet comes from your instances and services that go through source NAT (SNAT). The VMs and services use the same virtual IP (VIP) address as the incoming traffic. SNAT provides different benefits:
- It enables upgrade and disaster recovery of services, since the VIP can be dynamically mapped to another instance of the service.
- It reduces the access control list easier. ACLs expressed in terms of VIPs do not change as services scale up, down, or get redeployed.
The load balancer configuration supports full NAT for UDP. Full NAT is a type of NAT where the port allows inbound connections from any external host.
To learn more about the Azure network load balancer, you should visit the Microsoft MSDN source at https://azure.microsoft.com/en-us/documentation/articles/load-balancer-overview/.