vMotion error "Currently connected network interface" 'Network adapter 1' uses network "VM-portgroup", which is not accessible.

Products

• VMware vSphere ESXi

Issue/Introduction

• A vMotion migration attempted from a source host using a Standard Switch (vSS) to a destination host in a different cluster on a vSphere Distributed Switch (vDS) fails the compatibility pre-check. The validation wizard reports that 'Network adapter 1' is connected to 'VM-portgroup', which is identified as inaccessible at the destination compute resource.
  
  
  
  
• This migration involves moving a VM from a source host using Standard Switch networking to a destination host in a different cluster that is part of a Distributed Switch (vDS).

Environment

VMware ESXi

VMware vCenter Server

Cause

The "inaccessible network" error is a pre-check validation failure triggered by a network configuration discrepancy between the source and destination virtual switch configurations. This occurs when the vMotion migration wizard fails to verify that the virtual machine's current network backing (the logical connection to the physical wire) is available on the target compute resource.

Essentially, the migration is halted because the destination host cannot satisfy the VM's requirement for its specific Port Group and VLAN ID.

Resolution

To resolve the compatibility error "Currently connected network interface" 'Network adapter 1' uses network "VM-portgroup", which is not accessible" the destination environment must be prepared to accept the virtual machine's network configuration.

• Port Group Alignment:
  While vCenter allows for manual network remapping during the vMotion wizard, the most efficient resolution is to ensure the destination host has access to a Port Group that mirrors the source.
  
  
  • For Automatic Mapping: Create a Distributed Port Group on the destination vDS with the exact same name (e.g., VM-port_group_name) as the source Standard Switch port group. This allows the vMotion validation engine to automatically pair the interfaces, bypassing manual remapping.
    
    
  • For Manual Mapping: If a different naming convention is used on the vDS (e.g., VM-PortGroup), we must manually select the target network during the "Select Networks" stage of the migration wizard to clear the compatibility flag.
    
    
• VLAN Integrity (Connectivity Requirement):  A successful vMotion validation does not guarantee post-migration connectivity. To ensure the VM remains reachable on the network:
  • The destination Port Group must be tagged with the same VLAN ID as the source.
  • The physical switch trunks (uplinks) connected to the destination ESXi host must be configured to allow that specific VLAN ID.

Additional Information

For more information on vMotion requirement, please refer -vMotion networking requirements