VCF Workload Domain Import Fails during Brownfield Validation due to Missing VMkernel Default Gateway

Products

VMware SDDC Manager / VCF Installer VMware Cloud Foundation

Issue/Introduction

When attempting to import a brownfield Workload Domain into VCF (specifically VCF Operations/SDDC Manager 9.x), the process fails during the inventory synchronization stage.

Error message on the SDDC manager UI

Import operation for import with id ######-###-###-###-############ failed internally. Command was python3 /opt/vmware/vcf/domainmanager/scripts/vcf-import-tool/vcf_brownfield.py import --skip-ssh-thumbprint-validation --sso-user [email protected] --domain-name <domain_name> --vcenter <vCenter> --internal-vcf-auth --nsx-deployment-spec-path /tmp/nsxDeploymentSpec.json --skip-nsx-overlay --output-dir /var/log/vmware/vcf/domainmanager/brownfield/######-###-###-###-############/ --non-interactive. Please check the log files

Domain manager logs shows following error /var/log/vmware/vcf/domainmanager/domainmanager.log

 ERROR [vcf_dm,#############] [c.v.e.s.o.model.error.ErrorFactory,dm-exec-22]  [####] IMPORT_OPERATION_FAILED Import operation for import with id ######-###-###-###-######## failed internally. Command was python3 /opt/vmware/vcf/domainmanager/scripts/vcf-import-tool/vcf_brownfield.py import --skip-ssh-thumbprint-validation --sso-user  [email protected] --domain-name <Domainame> --vcenter <vCenter FQDN> --internal-vcf-auth --nsx-deployment-spec-path /tmp/nsxDeploymentSpec.json --skip-nsx-overlay --output-dir /var/log/vmware/vcf/domainmanager/brownfield/######-###-###-###-########/ --non-interactive. Please check the log files located in /var/log/vmware/vcf/domainmanager/brownfield/######-###-###-###-########/ on the SDDC Manager appliance

Error in /var/log/vmware/vcf/domainmanager/brownfield/######-###-###-###-############ /vcf_brownfield.log

[ERROR] request_helper:31: Result status code from ESC[91minventory import: 500ESC[00m
[CRITICAL] import_domain:200: Could not import the information for the new domain in SDDC Manager: Could not import inventory into SDDC Manager. Please review '/var/log/vmware/vcf/commonsvcs/vcf-commonsvcs.log' for further details.

Error in /var/log/vmware/vcf/domainmanager/brownfield/######-####-####-####-#########/output/guardrails_report_############.csv

   "error_code": "OPERATION_ISSUE",
      "message": "Failed to find default gateway for device vmk2 in host <host fqdn>
      "remediation_message": null,
      "severity": "WARNING"

Environment

VMware Cloud Foundation 9.x

Cause

The VCF Brownfield import tool performs a audit of the networking stack on each ESXi host. For an import to be successful, VCF requires that mandatory VMkernel adapters—specifically those intended for vMotion (often vmk2) or VSAN—have valid networking parameters defined.

In this scenario, the validation failed because the gateway for the specified VMkernel adapter was left blank (null) (or in some cases it is not correctly inherited from the TCP/IP stack).

Resolution

To resolve this issue, you must manually define the gateway for the affected VMkernel adapter on every host within the cluster being imported.

Log in to the vCenter Server associated with the import.
Select the ESXi host identified in the error message.
Navigate to Configure > Networking > VMkernel adapters.
Select the adapter mentioned in the error (e.g., vmk2).
Click Edit.
Under IPv4 settings, ensure that the Gateway is not blank. If the adapter is using a custom TCP/IP stack (like the vMotion stack), ensure the default gateway for that specific stack is defined.
Click OK and repeat for all hosts in the cluster.
After confirming that each VMkernel interface has a valid route/gateway, restart the Workload Domain Import process from the SDDC Manager UI.