Is there a way to assign a Public IP to the network interface of a Azure VM without NAT to a private IP?

Question

This is for an Anynode SBC running within a Windows Server 2016 instance virtualized in Azure. Anynode does not function properly behind NAT. We have purchased and assigned a Public IP to the machine in the Azure Portal but cannot find a way to assign that IP directly to the network interface without it translating to a Private IP. We also cannot assign it manually from the OS level because we do not know the subnet or gateway.

Has anyone been able to successfully do this or is it impossible because of some sort of restrictions or load balancing Microsoft does with it's public IPs

Answer 1

Hi Corbin,

Unfortunately, due to the way Azure’s networking is designed, it’s not possible to bypass NAT and assign the Public IP directly to the VM’s network interface. This is because Azure uses Source Network Address Translation (SNAT) for outbound connections

Checking on the azure Marketplace there are a template to use that include trial with full support on the implementation by anynode and you can bring your own license.

• https://azuremarketplace.microsoft.com/en/marketplace/apps/te-systems.anynode-the-software-sbc?tab=Overview
• https://www.anynode.de/config-wizard/

From Azure perspective the Public IP address is not directly assigned to the network interface of the VM. Instead, it’s associated with the network interface. This means that the Public IP is used to access the VM from the public internet, but within the Azure network, the VM uses the private IP, here some additional references:

• https://learn.microsoft.com/en-us/azure/virtual-network/ip-services/associate-public-ip-address-vm?tabs=azure-portal
• https://learn.microsoft.com/en-us/azure/virtual-network/ip-services/associate-public-ip-address-vm?tabs=azure-portal

Let me know if this information help to address your problem.

Luis