Add the networking components to create the logical network topology in the NSX-T. You can create the same logical topology as your existing NSX-V or create a new topology, if necessary.

You must also pre-configure the networking services that are required for your applications to run before the VMs are moved to the new NSX-T.

The following procedure outlines the workflow for creating the NSX-T logical topology. For a detailed information about creating and configuring the networking objects, see the NSX-T Data Center Administration Guide. If you plan to create the topology using APIs, see the NSX-T Data Center API Guide for more information.

Procedure

  1. Add tier-0 and tier-1 gateways depending on the requirements of your NSX-T network topology.
  2. Add NSX-T overlay segments with the same subnet address as the Logical Switches in NSX-V. Similarly, add NSX-T VLAN segments with the same subnet address as the Distributed Virtual Port Group (DVPG) VLANs in NSX-V.
    Same subnet address helps in ensuring that the IP addresses of the workload VMs are retained after the VMs move to NSX-T segments.
  3. To migrate Distributed Firewall configuration from your NSX-V environment, ensure that the following requirements are met:
    • The overlay segments in NSX-T must have the same virtual network identifier (VNI) as the Logical Switches in NSX-V. You must use the NSX-T APIs to create the overlay segments. You cannot create overlay segments with the same VNI in the NSX Manager UI.
    • The VLAN segments in NSX-T must have the same VLAN IDs as the VLAN Distributed Virtual Port Groups in NSX-V.
      Note: VLAN Distributed Virtual Port Group must be associated only with a VLAN ID. VLAN Trunk is not supported.
  4. If Layer 3 services such as Network Address Translation, Load Balancing, VPN, and so on, are configured on your NSX-V Edge Services Gateway, configure equivalent services on the tier-1 or tier-0 gateway of your NSX-T environment. Make sure that both steps 4 and 5 are done.

    If Layer 3 services are not configured, skip steps 4 and 5 and proceed directly to step 6.

    Caution: Be careful not to enable route advertisement and Layer 3 services on the tier-1 gateway while the north-south traffic is being routed through the Edge Services Gateway. It can conflict with the NSX-V environment. Also, remember that your workload VMs are not yet moved to NSX-T. The best time to enable route advertisement and Layer 3 network services is when you are ready to switch the default gateway for north-south traffic to the NSX-T side.
    1. In NSX Manager, navigate to Networking > Tier-1 Gateways.
    2. Click the vertical ellipses next to the tier-1 gateway, and then click Edit.
    3. Expand the Route Advertisement section, and turn off all the toggle buttons for the L3 services.
      For example:

      Screenshot shows that the Route Advertisement for all L3 services is turned off.
  5. Connect the uplink interface of the tier-0 gateway to a transit VLAN segment.
    Optionally, configure dynamic route peering between tier-0 gateway and the north-facing physical routers. If you configure dynamic routing, ensure that Route Redistribution Status is turned off on the tier-0 gateway so that no subnets are advertised in the NSX-T environment. You must enable Route Redistribution Status when you are ready to switch the default gateway to the NSX-T side for routing the north-south traffic.
    1. In NSX Manager, navigate to Networking > Tier-0 Gateways.
    2. Click the vertical ellipses next to the tier-0 gateway, and then click Edit.
    3. Expand the Route Re-Distribution section, and turn-off the Route Re-distribution Status toggle button.
  6. Attach the overlay segments to the downlinks of the tier-0 or tier-1 gateway.
    Turn off Connectivity on the segment while the north-south traffic is being routed through the Edge Services Gateway in your NSX-V environment. Turn on the segment connectivity only when you are ready to switch the default gateway to the NSX-T side for routing the north-south traffic.
    1. In NSX Manager, navigate to Networking > Segments.
    2. Click the vertical ellipses next to the segment, and then click Edit.
    3. Turn off the Connectivity option to disconnect the segment from the network topology.