Operational Defect Database

BugZero found this defect 762 days ago.

Veeam | kb4300

Veeam Backup & Replication Communication With Azure Proxy Fails With "The RPC server is unavailable"

Last update date:


Affected products:

Veeam Backup & Replication

Affected releases:


Fixed releases:

No fixed releases provided.



When attempting to add an Azure Restore Proxy Appliance to Veeam Backup & Replication or performing a Restore to Microsoft Azure using an Azure Restore Proxy Appliance, the following errors may occur: When attempting to add an Azure Restore Proxy Appliance:


This error occurs when the Veeam Backup Server or Backup Repository server cannot communicate with the Azure Restore Proxy Appliance. By default, this communication happens over port 443. The port used for communication can be changed. For more information, see Specify Credentials and Transport Port.


Review required ports and ensure communication from the Backup server or backup repository to Azure restore proxy appliance.   In addition to checking local routers and firewalls to ensure outbound traffic to the Azure Restore Proxy Appliance over port 443[1] is allowed, review the following Azure side configuration: Check if the Azure Subnet that the Azure Proxy is using is associated with an Azure Firewall or a Network Security Group (NSG).   For subnet associated with NSG Review the existing NSG rules, and if not configured, allow connections from the Veeam Backup server over port 443[1]. Alternatively, an NSG rule can be created with the highest priority (100) to allow connections over 443[1] using Azure CLI, PowerShell, or the Web Portal. Reference: Azure Network Security Group   For subnet associated with Azure Firewall By default, the Azure Firewall denies all traffic. Review the Azure Firewall configuration and ensure that a rule collection is configured to allow the traffic over port 443[1]. If it is a restore of Linux based computer, also allow port 22. Reference: Azure Firewall Rules

More Information

As a workaround, for Azure Restores, you may elect not to use a proxy appliance. However, not using an Azure Restore Proxy Appliance may negatively impact restore performance.

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