VCF 9.x Deployment Fails at vMotion Network Connectivity Validation

Products

• VMware vCenter Server

Issue/Introduction

This article details troubleshooting steps for VCF 9.0 and 9.1 deployment failures during the "Validate vMotion Network Connectivity" pre-check.

Symptoms

• Installer pre-check fails with "vMotion Network Connectivity" error.
  
• ESXi hosts become "not responding" during configuration push.
• Deployment log shows packet loss during vMotion ping test.

Environment

VMware Cloud Foundation (VCF) 9.0.x, 9.1.x

Cause

1. Known installer bug where the VCF installer does not honor standby uplinks when the active vmnic is in use by VSS (vSwitch0).
2. Physical network misconfiguration, specifically MTU (Jumbo Frames) mismatch or incorrect VLAN tagging on ESXi uplink ports.
3. Incorrect vmnic mapping in preconfigured switch profiles.

Resolution

1. Apply Installer Workaround: If you suspect the installer bug, apply the following workaround to unblock the pre-check, refer (9.1 VCF Installer fails on "vMotion Network Connectivity" check and/or "vSAN Network Connectivity") for more details:

   • SSH to the SDDC Manager with the vcf user and type su -.
   • Update the application properties file: echo "validation.disable.network.connectivity.check=true" >> /etc/vmware/vcf/domainmanager/application.properties
   • Restart the service: systemctl restart domainmanager

2. Verify Physical Network (If Step 1 Fails): If the pre-check fails after the workaround, verify physical infrastructure:

   • Confirm Jumbo Frames (MTU 9000) are enabled on all physical switch ports involved in the vMotion path.
   • Run manual connectivity tests: vmkping -I vmkX -s 8972 -d <destination_IP> (8972 accounts for the ICMP header).

3. Validate Switch Profile:

   • Review preconfigured switch profiles to ensure they match physical cabling.
   • Consider bypassing default profiles and using a Custom Switch Configuration to explicitly map vmnics to required traffic types (Management, vMotion, NSX-Overlay).

Additional Information

• Ensure management network gateway settings are correctly applied at the physical switch level.
• If issue persists, please open a support case and attach the SDDC Manager bundle logs.