NVP‑vProxy: Workflows Intermittently Fail With "Unable to Bind Socket to Port 0 From Connection Port Range 0-0"

The NVP integration uses a vProxy appliance to perform VM backups. Backup workflows intermittently fail and some executions succeed while others fail with socket bind errors. The same error may affect other NetWorker workflows and processes on the server, not just vProxy backups. The NetWorker Management Console (NMC) workflow messages and the workflow log show the socket bind failure (policy, workflow, and action names vary per environment):

MM/DD/YYYY HH:MM:SS My_NSR_Name nsrworkflow NSR notice Starting Protection Policy 'My_Policy' workflow 'My_WorkFlow'. 
MM/DD/YYYY HH:MM:SS My_NSR_Name nsrworkflow NSR notice Starting action 'My_Policy/My_WorkFlow/My_BackupAction' with command: 'nsrvproxy_save -s My_NSR_Name -j 1568619 -L incr -p My_Policy -w My_WorkFlow -A My_BackupAction'. 
MM/DD/YYYY HH:MM:SS My_NSR_Name nsrworkflow SYSTEM error Unable to bind socket to port 0 from connection port range 0-0: Cannot assign requested address 
MM/DD/YYYY HH:MM:SS My_NSR_Name nsrworkflow SYSTEM error Unable to bind socket to port 0 from connection port range 0-0: Cannot assign requested address 
MM/DD/YYYY HH:MM:SS My_NSR_Name nsrworkflow NSR notice Action 'My_Policy/My_WorkFlow/My_BackupAction's log will be in '/nsr/logs/policy/My_Policy/My_WorkFlow/My_BackupAction_1568635.raw'. 
MM/DD/YYYY HH:MM:SS My_NSR_Name nsrworkflow NSR notice Action 'My_Policy/My_WorkFlow/My_BackupAction' failed. 
MM/DD/YYYY HH:MM:SS My_NSR_Name nsrworkflow SYSTEM error Unable to bind socket to port 0 from connection port range 0-0: Cannot assign requested address 
MM/DD/YYYY HH:MM:SS My_NSR_Name nsrworkflow SYSTEM error Unable to bind socket to port 0 from connection port range 0-0: Cannot assign requested address 
MM/DD/YYYY HH:MM:SS My_NSR_Name nsrworkflow NSR notice Action 'My_Policy/My_WorkFlow/My_BackupAction log '/nsr/logs/policy/My_Policy/My_WorkFlow/My_BackupAction_1568635.raw' is empty. 
MM/DD/YYYY HH:MM:SS My_NSR_Name nsrworkflow NSR notice Workflow 'My_Policy/My_WorkFlow' failed.

The NetWorker server operating system has exhausted its available sockets. When a NetWorker process (such as nsrworkflow, nsrvproxy_save, or any other daemon) attempts to bind to a socket, the operating system cannot assign an ephemeral port because all available ports in the ephemeral port range are in use or in a TIME_WAIT state.

This is an environmental/OS-level issue, not a NetWorker or vProxy software defect. The socket exhaustion can be caused by:

• The default kernel settings for the maximum number of open file descriptors, ephemeral port range, or socket buffer sizes may be too small for the NetWorker workload.
• A large number of short-lived connections from concurrent backup operations can leave many sockets in the TIME_WAIT state, temporarily consuming the available port range.
• Other applications on the NetWorker server consuming sockets and reducing availability for NetWorker processes.

The issue is intermittent because socket availability fluctuates as connections are established, completed, and released through the TIME_WAIT cycle.

Review and optimize the operating system kernel parameters for the NetWorker server. Refer to the following sections in the Dell NetWorker Performance Optimization and Planning Guide:

• NetWorker kernel parameter requirements
• TCP buffers

The Dell NetWorker Performance Optimization and Planning Guide is available at: https://www.dell.com/support/product-details/product/networker/docs