The workload VMs on the NSX-V bridged Logical Switch are currently using the Distributed Logical Router (DLR) as their default gateway for all the north-south traffic.

When you are ready to migrate workload VMs to the bridged overlay segment, you must make the following configuration changes:
  • Switch the default gateway to NSX-T. In other words, the migrated VMs must connect to the tier-1 gateway as their default gateway for all north-south traffic. If your NSX-T environment has a single tier routing topology, you can switch to the tier-0 gateway.
  • If you have pre-configured Layer 3 network services on the tier-1 or tier-0 gateway, and dynamic route peering between tier-0 gateway and north-facing physical routers, do the following configurations:
    • On the tier-1 gateway, turn on Route Advertisement and Layer 3 services.
    • On the tier-0 gateway, turn on Route Re-distribution Status.

When the bridged overlay segment is connected to the NSX-T gateway, a GARP (gratuitous ARP) message will be sent and all connected VMs (including the NSX-V VMs) can update their ARP table accordingly.

You can make these configurations changes either manually or automate them by running APIs in a script file. Automation can help you to minimize the data traffic outage.

The following procedure explains the manual method of switching the default gateway to the tier-1 or tier-0 gateway in NSX-T by using the UI when Layer 3 services are not configured. For a minimum data traffic outage, you can automate the switching process with APIs.


Perform the procedure in Change the MAC Address of NSX-T Virtual Distributed Router so that the NSX-V VMs can reach the default gateway in NSX-T.


  1. In the NSX-V environment, disconnect the bridged Logical Switch from the DLR.
    1. In the vSphere Client, navigate to the NSX Edge (DLR).
    2. Click Configure > Interfaces.
    3. Select the internal interface on the DLR that is connected to the bridged Logical Switch and click Disconnect.
  2. In the NSX-T environment, connect the bridged overlay segment to the tier-1 gateway.
    1. In NSX Manager, navigate to Networking > Segments.
    2. Next to the name of the bridged overlay segment, click the vertical ellipses, and then click Edit.
    3. Turn on the Connectivity of the overlay segment, and click Save.