Operational Defect Database

BugZero found this defect 39 days ago.

Veeam | kb4557

"Established connection failed because connected host has failed to respond :10005"

Last update date:


Affected products:

Veeam Backup & Replication

Veeam Agent for Microsoft Windows

Affected releases:


Fixed releases:

No fixed releases provided.



A Windows Agent Backup or Windows Agent Policy type job within Veeam Backup & Replication fails with either of the following errors. A Veeam Agent Backup operating in Managed by backup server fails with the error: Error: Managed session has failed: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond <vbr_ip>:10005


These errors occur when the Windows machine where Veeam Agent for Microsoft Windows is installed cannot reach the Veeam Backup Service on the Veeam Backup Server over port 10005. This may occur if: The machine where Veeam Agent for Microsoft Windows is deployed cannot resolve the hostname or FQDN of the Veeam Backup Server. The Veeam Backup Service could not assign itself port 10005 when it started because another application already used that port. A firewall in the environment is blocking traffic between the machine where Veeam Agent for Microsoft Windows is installed and the Veeam Backup Server. Firewall on the Veeam Backup Server Firewall on the Windows machine itself. Firewall in the network (if the traffic is crossing them).


A complete guide on how to test port connectivity can be found on KB4444.

More Information

Customize Port Used To Recieve Communication If you are facing a situation where another product is using port 10005, and that third-party software cannot be adjusted to use a different port, Veeam Backup & Replication can be configured to listen on a different port for communication from managed Veeam Agent for Microsoft Windows deployments. Considerations and Limitations Changing the port that managed Veeam Agent for Microsoft Windows deployments use to communicate with Veeam Backup & Replication will cause them to lose contact with Veeam Backup & Replication until their configuration is updated to make them aware of the port change. For machines not in a Computer with pre-install backup agents type Protection Group, when Veeam Backup & Replication connects out to the Veeam Agent for Microsoft Windows deployment (job start or protection group rescan), it will update that deployment with the new inbound communication port. For machines in a Computer with pre-install backup agents type Protection Group, each machine must be manually reconfigured to communicate with Veeam Backup & Replication over the new port. This is because machines in that type of Protection Group cannot have a configuration pushed out to them; they receive their configuration instead by periodically contacting the Veeam Backup & Replication server to see if their job settings have changed. Therefore, changing the inbound communication port causes them to no longer be able to reach the Veeam Backup & Replication software. To update the machine in this type of protection group, either: Update configuration using the Configurator — Generate a new pre-configured deployment package, copy the <protection_group_name>.xml configuration file to the Windows machine, then use the following command to update the configuration:"C:\Program Files\Veeam\Endpoint Backup\Veeam.Agent.Configurator.exe" -setVBRsettings /p:"<protection_group_name>.xml" or Update the port by editing the registry — Edit the SerializedConnectionParamsstring value in the [HKLM\SOFTWARE\Veeam\Veeam EndPoint Backup] key on the Windows machine. The string value will contain a port number; update that to match the port selected on the Veeam Backup Server.<?xml version="1.0"?><ConnectionParams ConnectionPoint="VBR.domain.tld" Port="10005"><IpAddresses></IpAddresses></ConnectionParams>   Registry Value Create the following registry value on the Veeam Backup Server.Key Location: HKLM\SOFTWARE\Veeam\Veeam Backup and Replication\ Value Name: EndPointServerSslPort Value Type: DWORD (32-Bit) Value Value Data(Dec): 10005 (Default)

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