Vmss lack of IP Issue

Question

We have some vmss in a subnet but due to lack of IP address in subnet. We are planning to create new subnet. Here which is better option to increase existing subnet or create new subnet. If create new subnet then how does vmss which was part of old subnet will accommodate.

Answer 1

Hi Shailesh,

For your need for additional IP addresses in your Azure Virtual Machine Scale Set (VMSS);

• Increase Existing Subnet (if possible) because Expanding the existing subnet might be limited by the maximum number of available IP addresses.
  • cons; If other resources (like VMs or other services) are already using the subnet, expanding it could impact them.
• Create a New Subnet
  • cons: You’ll need to update your VMSS configuration to use the new subnet
  • cons: Existing VMSS instances will need to be moved to the new subnet.

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Answer 2

Hello Shailesh Ganesh Shripati,

Thanks for your question.

As a short-term solution, you can increase the subnet address range if there is enough space for a quicker fix.

for future-proofing, I will recommend creating a new subnet for better flexibility and future scalability. However, this may be more complex and will require planning.

See:

https://learn.microsoft.com/en-us/azure/cloud-adoption-framework/ready/azure-best-practices/plan-for-ip-addressing?source=recommendations

Regards,

You can mark it 'Accept Answer' if this helped.