If an extended segment is specified in the migration settings, a warning message appears indicating that the connection to the virtual machine may be lost.

Products

• VMware HCX

Issue/Introduction

• When performing a VM Migration using VMware HCX, the following warning message may appear during the VALIDATE phase even when the destination network is a correctly configured L2 Extended segment:
  

  VM may lose network connectivity after the migration because of the change in destination network(s) : <Network_Name>

• The results of validation checks displayed in the UI are recorded in web.log.
  /common/logs/admin/web.log
  

  <timestamp> UTC [https-jsse-nio-8443-exec-8, Ent: HybridityAdmin, , TxId: TxId: <uuid>] INFO  c.v.v.h.a.m.c.MobilityIntentInteropUtil- mobility migration quick validation has been initiated with input: {"migrationGroupId":"<uuid>","migrations":[{"schedule":"scheduledFailover":false},"target":
  
  <snip>
  
  "networks":{"targetNetworks":[{"srcNetworkValue":"dvportgroup-<number>","srcNetworkHref":"dvportgroup-<number>","srcNetworkType":"DistributedVirtualPortgroup","srcNetworkName":"<network-name>"
  
  <snip>
  
  "validationInfo":{"validationResult":{"warnings":[{"message":"VM may lose network connectivity after the migration because of the change in destination network(s) : (<network-name>)"}]}},

• The migration completes successfully, and the VM maintains network connectivity without disruption.

Environment

VMware HCX

Cause

This issue is caused by a limitation in how HCX detects network identity in environments where multiple VDS are used within the same Transport Zone in NSX.

When NSX segments are created across different VDS instances, they are assigned different port group identifiers per VDS instance.
(e.g., VDS-A : dvportgroup-<number-a> vs VDS-B : dvportgroup-<number-b>)

When the network is first extended, HCX stores the specific port group identifier present on the ESXi host where the NE is installed in its internal database.

The verification logic compares the port group identifier currently connected to the target VM with the information stored in the HCX database.

If the VM is on a host where the segment is backed by a different internal port group number than the one registered during the initial L2 Extension, the validation engine triggers a warning, assuming the network is unextended or different, even if they belong to the same logical NSX segment.

Resolution

This will be fixed in a future release.

This message is a UI validation warning and can generally be ignored if you have verified that the L2 Extension is healthy and the destination network is correct.

Verify Connectivity: Confirm that other VMs on the same extended segment are communicating correctly across sites.
Proceed with Migration: If L2 extension is confirmed as active, you may proceed with the migration. As observed in field cases, connectivity is typically maintained post-migration.