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. 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 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 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 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.

Prerequisites

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

Procedure

  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 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.