vCenter server upgrade fails in stage 2 with an error: "Failed to set network"

Products

• VMware vCenter Server 7.0
• VMware vCenter Server 8.0

Issue/Introduction

• While upgrading vCenter server 7.0.x to 8.0.x upgrade fails at 50% in stage 2 "Applying networking configuration" fails with error: "Failed to set network"
• vCenter server was changed to IPv6 settings.
• Logs in vCenter server 8.0.x located at  /var/log/vmware/upgrade/upgrade-export.log shows below errors

 YYYY-MM-DDThh:mm:ss.Z ERROR transfer_network Fatal error during upgrade network transferred.
       Traceback (most recent call last):
       File "/usr/lib/vmware/cis_upgrade_runner/bootstrap_scripts/transfer_network.py", line 1327, in execute
       _validateNetworkConfiguration(networkConfig)
       File "/usr/lib/vmware/cis_upgrade_runner/bootstrap_scripts/transfer_network.py", line 969, in _validateNetworkConfiguration
       raise NetworkConfigError(error)
       apply_networking.NetworkConfigError: Could not migrate IPv4 network configuration.

 

Cause

If the vCenter server is initially deployed with IPV4 settings and later the vCenter IP address was changed to IPV6 . The file in /etc/vmware/install-defaults  "appliance.net.addr.family" does not change its value from ipv4 to ipv6 automatically 

 

Resolution

To resolve the issue, change the value of the appliance.net.addr.family file in the source vCenter server.

Perform the below steps 

1. Connect to the vCenter Server Appliance through SSH. For more information, see Enable or Disable SSH and Bash Shell Access
2. Log in as root.
3. Type shell to enter in shell mode 
4. Type cd /etc/vmware/install-defaults
5. Edit the file using command vi appliance.net.addr.family 
6. Change ipv4 to ipv6
7. Save the file by pressing "Esc" button then type  :wq!
8. Restart the upgrade process. 

NOTE: - Before making any changes, take snapshot of the vCenter server. If the VCs are in ELM, take offline snapshot in powered off state.