vCenters no longer connecting since update to 8.18.5

Products

• VCF Operations/Automation (formerly VMware Aria Suite)

Issue/Introduction

After upgrading to Aria Operations 8.18.5, vCenter adapters stop collecting metrics and enter a "Warning" state. The following status messages are displayed in the user interface:

• Unable to connect to VC
• Object down

The "Validate Connection" action fails intermittently with "Connection refused" or "Error trying to establish connection."

Logs on the collector node (/storage/log/vcops/log/adapters/VMwareAdapter/VMwareAdapter_ID.log) contain the following error:

java.net.NoRouteToHostException: No route to host ( Host unreachable )

Environment

Aria Operations 8.18.5

Cause

This issue is caused by a network configuration error on the underlying network infrastructure (such as core switches). Specifically, missing syntax in static route configurations (e.g., a missing "tag" parameter) can cause traffic to be dropped or misrouted when Aria Operations attempts to resolve and connect to the vCenter via FQDN, even if IP-based connectivity appears functional.

Resolution

To resolve this issue, you must verify the network path and correct the switch configuration.

1. Verify the connectivity discrepancy

   Log in to the Aria Operations node (or Cloud Proxy) via SSH and run the following commands to test connectivity to the vCenter.

   Test connection using the IP address:

   curl -k telnet://<VC_IP_Address>:443

   • Expected result: Connected

   Test connection using the FQDN:

   curl -k telnet://<VC_FQDN>:443

   • Expected result: Failed ("Could not connect") or intermittent failure.
     
     
2. Correct the network configuration

   Engage your network team to review the configuration of core switches and firewalls between the Aria Operations nodes and the vCenter.

   • Identify any static routes missing required parameters (such as a "tag").
   • Apply the necessary configuration changes to ensure FQDN traffic is routed correctly.
     
     
3. Validate the adapter

   Once the network changes are applied, return to the Aria Operations UI:

   • Navigate to Administration > Integrations.
   • Select the affected vCenter adapter instance.
   • Click Validate Connection to confirm the connection is successful.
   • Ensure metric collection resumes and the status returns to "OK".