Upgrade of vcenter appliance is failing from 6.x to 7.0u3 at stage 2 export phase-50% due to network error

Products

• VMware vCenter Server 6.0

Issue/Introduction

*Source vcenter is powered off.
*Target vcenter is still running with temp ip address.
*Source vcenter has more than 1 network adapter.
*Upgrade is failing at stage 2, export phase- 50%

Environment

VCSA 6.5
VCSA 6.7

Cause

Only 1 network adapter is allowed on vcsa 6.x and customer is using 2 network adapters on vcenter 6.x

 

20xx-0x-xxT00:52:58.935Z INFO apply_networking Network adapter eth1 present in ['eth0']: False
20xx-0x-xxT00:52:58.935Z INFO apply_networking Checking network adapter eth1
20xx-0x-xxT00:52:58.947Z INFO apply_networking Interfaces found by vami_interfaces : eth0
eth1

2025-07-23T00:52:58.948Z 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 1155, in execute
    interface)
  File "/usr/lib/vmware/cis_upgrade_runner/bootstrap_scripts/transfer_network.py", line 867, in _updateTargetNetworkConfig
    if createNetworkFile(networkConfig, interface):
  File "/usr/lib/vmware/cis_upgrade_runner/bootstrap_scripts/apply_networking.py", line 128, in createNetworkFile
    ipflag = getIpFamily(networkConfig['config_flags'])
KeyError: 'config_flags'
20xx-0x-xxT00:52:58.951Z ERROR __main__ ERROR: Fatal error during upgrade EXPORT. For more details take a look at: /var/log/vmware/upgrade/export-upgrade-runner.log
20xx-0x-xxT00:52:58.951Z WARNING root stopping status aggregation...
20xx-0x-xxT00:52:58.955Z INFO __main__ Merging source and destination repositories
20xx-0x-xxT00:52:58.959Z INFO __main__ Source and destination repositories have been merged
20xx-0x-xxT00:52:58.959Z INFO root Exiting with exit-code 1

 

Resolution

Disconnected the unsued second network adapter from source vcenter and resumed the upgrade from 2nd stage directly.