NSX-V to NSX-T migration using Migration Coordinator may fail if the source Edge has multiple Uplinks connected to same VLAN but different VDS

Products

• VMware NSX

Issue/Introduction

• NSX-V to NSX-T migration fails during migration stage " Translate Configuration Layer 2" .
• Source NSX-V has ESG's with multiple interfaces , connected to same VLAN portgroup on different VDS . 

Error in UI : 
Config translation failed [Reason: [Transport Zone] Can not proceed with migration: Edge VMs connect to DVPGs with same vlan 701on more than 1 overlay DVSes dvs-##,dvs-^^.Edge VMs connect to DVPGs with same vlan 702on more than 1 overlay DVSes dvs-##,dvs-^^.]

Migration-coordinator.log
2024-08-19T08:23:21.057Z  INFO http-nio-127.0.0.1-7450-exec-1 MigrationFacadeImpl 3476 SYSTEM [nsx@6876 comp="nsx-manager" level="INFO" subcomp="migration-coordinator"] Unit: ConfigCollectorL2, status: FAILED, % complete: 0.0, errors: Config translation failed [Reason: [Transport Zone] Can not proceed with migration: Edge VMs connect to DVPGs with same vlan 701on more than 1 overlay DVSes dvs-##,dvs-^^.Edge VMs connect to DVPGs with same vlan 702on more than 1 overlay DVSes dvs-##,dvs-^^.]Config translation failed [Reason: ]

Environment

VMware NSX-T Datacenter 
VMware NSX 4.x

Cause

This validation was in place to inform customers that Migration coordinator do not support migrating this topology ( source side with ESG's having multiple interfaces , connected to same VLAN portgroup and different vDS) as a part of full migration , where Migration coordinator has to auto-create NSXT edge TN's and T0 LR's. 

Resolution

The Validation Blocker for this condition is improved in NSX-T 3.2.5 and NSX-T 4.2.1 . 
Please Note : The above said Topology is only supported in BYOT mode of migrations . While the code improvement can skip the validation Blocker , the end topology at the target side should be defined by the user .