SDDC Manager Add Cluster Wizard Hangs When Reusing NSX Edge VDS Configuration - ERROR: "Unable to get vlanId for portgroup"

Products

• VMware Cloud Foundation

Issue/Introduction

In the VMware Cloud Foundation (VCF) SDDC Manager UI, the "Add Cluster" wizard stalls on the Distributed Switch step when attempting to reuse the network configuration of an existing cluster that has an NSX Edge deployed.

• The NEXT button remains permanently disabled.

• No error message is displayed in the user interface.

• NIC mapping auto-populates, but the wizard cannot proceed.

• The /var/log/vmware/vcf/domainmanager/domainmanager.log file contains the following backend error signatures: Unable to get vlanId for portgroup <id> java.lang.ClassCastException: class com.vmware.vim.binding.vim.dvs.VmwareDistributedVirtualSwitch$TrunkVlanSpec cannot be cast to class com.vmware.vim.binding.vim.dvs.VmwareDistributedVirtualSwitch$VlanIdSpec

 

Environment

VMware Cloud Foundation 5.2.x

VMware Cloud Foundation 9.1.1

SDDC Manager 5.2.x

SDDC Manager 9.1.1

Cause

This issue occurs because the selected source cluster contains NSX Edge uplink port groups configured with a VLAN trunk (TrunkVlanSpec). When SDDC Manager queries the distributed switch configuration to clone it, it expects a single VLAN ID (VlanIdSpec).

This mismatch triggers a silent ClassCastException on the backend, resulting in an incomplete network details payload being returned. Without a complete configuration to clone, the wizard's progression is permanently blocked.

 

Resolution

This issue is addressed in a future release of VMware Cloud Foundation. To bypass this issue in affected versions, utilize the following workaround:

1. In the Add Cluster wizard, navigate to the Distributed Switch step.

2. Do not select the "Reuse existing cluster network configuration" option for any cluster that currently has an NSX Edge deployed.

3. Select the custom VDS creation option instead.

4. Choose one of the following methods to proceed:

   • Method A (Identical configuration): Manually re-create the source cluster's distributed-switch configuration. Ensure you match the port group names exactly when defining the VDS for the new cluster.

   • Method B (New port groups): Choose to re-use the VDS but manually specify new port groups for the new cluster.

5. The NEXT button will now enable, allowing you to continue the cluster creation process.

 

Additional Information

For more information on VCF deployment and known issues, consult the VCF product documentation at Broadcom TechDocs.