HCX Migration Attempt Shows the Following Warning, "Selected target network(s) has ephemeral binding. VM will be migrated with NIC being disconnected."

Products

• VMware HCX

Issue/Introduction

During HCX migration operations, users may encounter a warning message stating: "Selected target network(s) has ephemeral binding. VM will be migrated with NIC being disconnected." This occurs when attempting to migrate VMs to networks configured with ephemeral binding.

Environment

• VMware HCX
• Distributed Virtual Switch (DVS) with ephemeral binding portgroups
• Source and target environments configured for HCX migration

Cause

HCX does not support network connectivity when migrating to portgroups configured with ephemeral binding. This is because

• Ephemeral binding assigns port numbers at the host level
• During migration, this can result in disconnected NICs that don't automatically reconnect after migration completion
• HCX requires static binding for network extension support

Resolution

There are several approaches to resolve this issue

Option 1 (Recommended for small-scale migrations)

1. Proceed with the migration understanding NICs will disconnect
2. Manually reconnect VM network adapters post-migration using either:
   • vSphere UI: Edit VM settings and check "Connected" and "Connect at power on"
   • PowerCLI: Use Set-NetworkAdapter with -Connected and -StartConnected parameters

Option 2 (For larger-scale migrations where network changes are feasible)

1. Create a new portgroup with static binding and a different VLAN
2. Migrate VMs to the new portgroup
3. Remove old portgroup
4. Recreate original portgroup with static binding
5. Move VMs back to the original network if desired

Note: When working with management networks or critical infrastructure, it's often safer to use Option 1 and manually reconnect NICs rather than modifying network configurations.