Veeam backup fails because data-agent is not healthy on port 16443

Issue/Introduction

Source and classification

• Source: Site case from the veeam &Commvault使用说明 group.
• Classification: Prerequisite component installation or connectivity issue before Veeam backup.
• Confirmation basis: During a Kaspersky Server backup, Veeam reported that data-agent did not pass the health check on 16443 after installation. Another multi-management-node case confirmed that local installation might deploy only on the current node; other nodes do not automatically receive parameters and require deploy.
• Internal tracking: No specific Jira.

Issue metadata

• Issue ID: None.
• Component/product: ZSphere, Veeam Data Agent, and API Proxy deployment components.
• Status: Troubleshooting and a multi-MN workaround are available; determine cause from listener, service log, and connectivity.
• Priority/severity: General; blocks backup on the affected host or VM.
• Confirmed version: Compatible Veeam version 13.1.1.18.
• First fixed version: None.
• Confirmation date: August 13, 2026.
• Last updated: September 4, 2026.

Problem description

Before backup, Veeam installs or checks data-agent on the relevant host and accesses 16443 to confirm readiness. Health check fails if service is not started, the port is not listening, a network/firewall blocks access, or a multi-MN deployment installed the component on another node.

The complete site error is:

2026/8/13 13:55:40 :: Kaspersky Server : Failed to perform backup: host data-agent did not become healthy on 172.27.220.211:16443 after installation

This proves only that Veeam could not confirm readiness on that IP, not whether service startup, installation placement, or network failed. Identify the IP's node, then inspect installation, port, and path.

Symptoms

• Backup fails while installing or checking data-agent.
• Task logs show:

  Failed to perform backup: host data-agent did not become healthy on <IP>:16443 after installation

• Port 16443 might not listen on the addressed node.
• In a multi-MN environment, only the locally installed node might listen.
• Even with a listener, routing, firewall, or wrong address might block Veeam.

Site screenshot

Impact

• Backups using the affected node fail.
• Other correctly deployed and reachable nodes might be unaffected.
• There is no evidence of damage to existing backups or VM disks.
• Repeated installation/uninstall before diagnosis might overwrite logs.

Environment

• Product: ZSphere and Veeam integration.
• Product line: ZVF.
• Component: Veeam Data Agent and related deployment components.
• Confirmed version: Veeam 13.1.1.18; assess other versions separately.
• Trigger: The specified node's data-agent does not pass health check on 16443 after installation, or Veeam cannot reach it.