In Azure, there are certain limitations on the number of public IP addresses you can have per subscription, especially with free or student accounts. Typically, Azure free or student subscriptions have limited resources, including the number of public IP addresses you can use. If you've reached the limit of three public IP addresses per subscription, you have a few options:
- Use an existing IP address: If one of the existing public IP addresses is not actively in use, you might be able to reassign it to the load balancer for the health probe.
- Delete unused resources: If you have any unused resources in your subscription, such as virtual machines, storage accounts, or other resources, consider deleting them to free up resources, including public IP addresses.
- Upgrade your subscription: Azure free or student subscriptions have limitations on resources. Consider upgrading your subscription to a paid subscription tier, which typically offers more resources, including the ability to create more public IP addresses.
- Request a limit increase: If you have a specific need for additional resources, you can request a limit increase from Azure support. However, this might not be available for free or student subscriptions.
- Optimize your architecture: Review your architecture and see if you can optimize it to use fewer public IP addresses. For example, you might be able to consolidate resources or use network address translation (NAT) to share IP addresses.
- Consider using Azure Application Gateway: Instead of using individual public IP addresses for each virtual machine, you could use Azure Application Gateway, which can route traffic to multiple backend servers using a single public IP address. This can help reduce the number of IP addresses needed.
https://learn.microsoft.com/EN-us/azure/application-gateway/quick-create-portal?wt.mc_id=MVP_328341
Keep in mind that Azure free or student subscriptions are primarily for learning and experimentation purposes, and they have limitations compared to paid subscriptions. If your project or requirements exceed the limitations of the free or student subscription, you might need to consider upgrading to a paid subscription tier.