Procedures for vCenter Server Migration and IP Address Change in NSX-T Environments

Products

• VMware NSX

Issue/Introduction

When migrating a vCenter Server Appliance (VCSA) that is registered as a Compute Manager in VMware NSX, changes to the vCenter IP address or its management environment can cause management plane disconnection, host isolation, or "Compute Manager Down" status.
This article provides the decommissioning and re-registration steps required to maintain NSX-T functionality during a vCenter IP change or cluster migration.

Environment

 VMware NSX

Cause

NSX-T identifies a Compute Manager by its FQDN or IP address. If the IP changes, the underlying trust and communication between the NSX Manager and vCenter are interrupted.
Furthermore, if the vCenter is moved to a new cluster or management vCenter, existing dependencies (Host Transport Nodes, Edges, UI-deployed appliances) must be reconciled to prevent orphaned objects.

Resolution

Prerequisites

• Run a full NSX configuration backup.
• Take an offline snapshot and grab a file-based backup of your vCenter Server Appliance (VCSA).
• Check whether your NSX Managers and Edges were deployed straight from the NSX UI or manually using an OVA file.

Decommissioning the Source vCenter

Before migrating the vCenter to a new IP or cluster, you must decouple it from the source NSX Manager in the following top-down order:

1.Uninstall NSX from ESXi Hosts:

• Evacuate workload VMs from NSX segments.
• In the NSX UI, navigate to System > Fabric > Nodes > Host Transport Nodes.
• Select the cluster/hosts and click Remove NSX. (Detach Transport Node Profiles first if applicable).

2.Delete UI-Deployed Edge Nodes:

• Disconnect all Segments from Tier-1/Tier-0 gateways.
• Delete BGP neighbors and gateways.
• Navigate to System > Fabric > Nodes > Edge Clusters, remove Edges from the cluster, then delete the Edge Transport Nodes.

3.Remove the Compute Manager:

• Navigate to System > Fabric > Compute Managers.
• Select the vCenter and click Delete. Confirm to unregister the "NSX Extension" from vCenter.

vCenter Migration and IP Change

• Clone/Migrate vCenter: Move the VM to the destination cluster/vCenter.
• Update IP via VAMI:
• Log in to the VCSA via SSH.
  • Run: /opt/vmware/share/vami/vami_config_net
  • Follow the prompts to update the IP address, Gateway, and Netmask.
• Reboot the appliance.
• Reconcile DNS: Ensure the vCenter FQDN now resolves to the new IP <new_vcenter_ip> in your DNS (A and PTR records).

Re-registering with NSX-T

• Verify Connectivity: Ensure the NSX Manager can reach the new vCenter IP over ports 443 and 80.
• Add Compute Manager:
  • In NSX UI, navigate to System > Fabric > Compute Managers > Add.
  • Enter the FQDN and credentials.
• Accept Thumbprint: If prompted with an "Invalid Thumbprint" error, edit the Compute Manager and accept the new SSL thumbprint to restore trust.
• Re-prepare Hosts: Apply the Transport Node Profiles to the new clusters as needed.

Workaround: If only the IP is changing (and not the management cluster), ensure the vCenter Server Managed Address is updated in vCenter > Configure > Runtime Settings to match the new IP, then re-sync the Compute Manager in the NSX UI.

Additional Information

Best practices for changing the IP address of vCenter Server.
ESXi hosts show as "Not Responding" after vCenter IP change.
Requirements for NSX-T Compute Manager.