Edit

Guidance for Virtual Machine Scale Sets with Azure Load Balancer

  • Article

When you work with Virtual Machine Scale Sets and Azure Load Balancer, consider the following guidelines.

Port forwarding and inbound NAT rules

After the scale set has been created, the backend port can't be modified for a load-balancing rule used by a health probe of the load balancer. To change the port, remove the health probe by updating the virtual machine scale set and updating the port. Then configure the health probe again.

When you use the Virtual Machine Scale Set in the backend pool of the load balancer, the default inbound NAT rules are created automatically.

Load-balancing rules

When you use the Virtual Machine Scale Set in the backend pool of the load balancer, the default load-balancing rule is created automatically.

Virtual Machine Scale Set instance-level IPs

When Virtual Machine Scale Sets with public IPs per instance are created with a load balancer in front, the SKU of the Load Balancer (that is, Basic or Standard) determines the SKU of the instance IPs.

Outbound rules

To create an outbound rule for a backend pool that's already referenced by a load-balancing rule, select No under Create implicit outbound rules in the Azure portal when the inbound load-balancing rule is created.

Screenshot that shows load-balancing rule creation.

Use the following methods to deploy a Virtual Machine Scale Sets with an existing instance of Load Balancer: