| title | Troubleshoot common deployment errors |
|---|---|
| titleSuffix | Azure Load Balancer |
| description | Learn how to troubleshoot common Azure Load Balancer deployment errors, fix issues faster, and restore traffic flow—review the solutions now. |
| services | load-balancer |
| ms.service | azure-load-balancer |
| author | JarrettRenshaw |
| ms.author | jarrettr |
| manager | dcscontentpm |
| ms.topic | troubleshooting |
| ms.date | 04/06/2026 |
| ms.custom | template-concept, engagement-fy23 |
Use this article to troubleshoot common Azure Load Balancer deployment errors and resolve them quickly. Review the error codes and mitigations to restore load balancing for your applications.
| Error code | Details and mitigation |
|---|---|
| DifferentSkuLoadBalancersAndPublicIPAddressNotAllowed | Both Public IP SKU and Load Balancer SKU must match. Ensure Azure Load Balancer and Public IP SKUs match. Standard SKU is recommended for production workloads. Learn more about the differences in SKUs |
| DifferentSkuLoadBalancerAndPublicIPAddressNotAllowedInVMSS | Virtual Machine Scale Sets default to Basic Load Balancers when SKU is unspecified or deployed without Standard Public IPs. Redeploy Virtual Machine Scale Set with Standard Public IPs on the individual instances to ensure Standard Load Balancer is selected or select a Standard LB when deploying Virtual Machine Scale Set from the Azure portal. |
| MaxAvailabilitySetsInLoadBalancerReached | The backend pool of a Load Balancer can contain a maximum of 150 availability sets. If you don't have availability sets explicitly defined for your VMs in the backend pool, each single VM goes into its own Availability Set. So deploying 150 standalone VMs would imply that it would have 150 Availability sets, thus hitting the limit. You can deploy an availability set and add more VMs to it as a workaround. |
| NetworkInterfaceAndLoadBalancerAreInDifferentAvailabilitySets | For Basic Sku load balancer, network interface and load balancer have to be in the same availability set. |
| RulesOfSameLoadBalancerTypeUseSameBackendPortProtocolAndIPConfig | You can't have more than one rule on a given load balancer type (internal, public) with same backend port and protocol referenced by same Virtual Machine Scale Set. Update your rule to change this duplicate rule creation. |
| RulesOfSameLoadBalancerTypeUseSameBackendPortProtocolAndVmssIPConfig | You can't have more than one rule on a given load balancer type (internal, public) with same backend port and protocol referenced by same Virtual Machine Scale Set. Update your rule parameters to change this duplicate rule creation. |
| AnotherInternalLoadBalancerExists | You can have only one Load Balancer of type internal reference the same set of VMs/network interfaces in the backend of the Load Balancer. Update your deployment to ensure you're creating only one Load Balancer of the same type. |
| CannotUseInactiveHealthProbe | You can't have a probe that's not used by any rule configured for Virtual Machine Scale Set health. Ensure that the probe that is set up is being actively used. |
| VMScaleSetCannotUseMultipleLoadBalancersOfSameType | You can't have multiple Load Balancers of the same type (internal, public). You can have a maximum of one internal and one public Load Balancer. |
| VMScaleSetCannotReferenceLoadbalancerWhenLargeScaleOrCrossAZ | Basic Load Balancer isn't supported for multiple-placement group Virtual Machine Scale Sets or cross-availability zone Virtual Machine Scale Set. Use Standard Load Balancer instead. |
| MarketplacePurchaseEligibilityFailed | Switch to the correct Administrative account to enable purchases due to subscription being an EA Subscription. You can read more here. |
| ResourceDeploymentFailure | If your load balancer is in a failed state, follow these steps to bring it back from the failed state: 1. Go to https://resources.azure.com, and sign in with your Azure portal credentials. 2. Select Read/Write. 3. On the left, expand Subscriptions, and then expand the Subscription with the Load Balancer to update. 4. Expand ResourceGroups, and then expand the resource group with the Load Balancer to update. 5. Select Microsoft.Network > LoadBalancers, and then select the Load Balancer to update, LoadBalancer_1. 6. On the display page for LoadBalancer_1, select GET > Edit. 7. Update the ProvisioningState value from Failed to Succeeded. 8. Select PUT. |
| LoadBalancerWithoutFrontendIPCantHaveChildResources | A Load Balancer resource that has no frontend IP configurations, can't have associated child resources or components associated to it. In order to mitigate this error, add a frontend IP configuration and then add the resources you're trying to add. |
| LoadBalancerRuleCountLimitReachedForNic | A backend pool member's network interface (virtual machine, Virtual Machine Scale Set) can't be associated to more than 300 rules. Reduce the number of rules or use another Load Balancer. This limit is documented on the Load Balancer limits page. |
| LoadBalancerInUseByVirtualMachineScaleSet | The Load Balancer resource is in use by a Virtual Machine Scale Set and can't be deleted. Use the Azure Resource Manager ID provided in the error message to search for the Virtual Machine Scale Set in order to delete it. |
| SpecifiedAllocatedOutboundPortsForOutboundRuleIsNotAMultipleOfEight | The number of specified SNAT ports isn't a multiple of 8. |
| SpecifiedAllocatedOutboundPortsForOutboundRuleExceedsTotalNumberOfAllowedPortsPerRule | The number of specified SNAT ports is greater than 64000. |
| SpecifiedAllocatedOutboundPortsForOutboundRuleExceedsTotalNumberOfAvailablePorts | The number of specified SNAT ports is greater than currently available. |
| LoadBalancerBackendsPerFrontendCountLimitReached | A frontend IP configuration on a Standard Load Balancer can't have more than 10,000 total backend IP configurations. Each load balancing rule, inbound NAT rule, or outbound rule configured to a backend instance counts as one backend IP configuration for the given frontend IP. To mitigate this issue, add additional frontend IP configurations (for example, using a Public IP prefix) or reduce the number of backend IP configurations associated with the frontend IP. |
- Look through the Azure Load Balancer SKU comparison table
- Learn about Azure Load Balancer limits