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I was going through AWS where they tend to keep Public IP for the vm instances and are able to configure the Loadbalancer,can we leave public IP here as well for individual vms.
I observe that if we add VM to backend pool while creating the VM, public IP of VM gets replaced by LB IP.
In other instance when attempting to add VM from LB backend pools blade,it does not display the VM till I manually remove Public IP even if VM has the Standard IP configured:

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VM configuration: enter image description here

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Cannot find clear answers online.

Regards,
Aditya

Aditya Garg
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1 Answers1

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Azure provides an ephemeral IP for Azure Virtual Machines which aren't assigned a public IP address, or are in the backend pool of an internal Basic Azure Load Balancer. The ephemeral IP mechanism provides an outbound IP address that isn't configurable.

The ephemeral IP is disabled when a public IP address is assigned to the virtual machine or the virtual machine is placed in the backend pool of a Standard Load Balancer with or without outbound rules. If a Azure Virtual Network NAT gateway resource is assigned to the subnet of the virtual machine, the ephemeral IP is disabled.

https://learn.microsoft.com/en-us/azure/virtual-network/public-ip-addresses#internet-facing-load-balancers

You need to configure an outbound rule on Load Balancer with Network Address Translation (NAT) for all virtual machines or instances identified by the backend pool. This rule enables instances in the backend to communicate (outbound) to the internet using VMs Public IP.

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https://learn.microsoft.com/en-us/azure/load-balancer/components#outbound-rules

https://learn.microsoft.com/en-us/azure/load-balancer/load-balancer-outbound-connections#assigning-a-public-ip-to-the-virtual-machine

Andriy Bilous
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