NAT Gateway functionality in Azure
When we attach Azure Standard Internal Gateway then internet stopped working in the Azure VM (behind the Std ILB). There are two workaround to tackle this issue:
1. Assign Individual IP to each and every Azure VM
2. Put these all VMs behind the new Std Public LB with the same custom health probe which we have used in Std ILB, and creating any random LB rule based on this custom HP (Like workaround).
There are below challenges with above soluntions:
1. It is costly as there is some cost associated with each ***** ip.
2. It is workaround which would stop working when health port is not responding in VM.
Documentation states that this is because "When only an internal Load Balancer is serving a virtual machine, outbound connections via default SNAT are not available".
Now my point when it comes to enterprise solutions Microsoft is considered to come in this case with some more robust solution like NAT Gateway.
NAT Gateway would allow a passage to internet irrelevant to its part of any kind of Load Balancer.