Connectivity loss with Layer 2 Bridging for Lift-and-Shift Migration with NSX-T Federation

Products

• VMware NSX

Issue/Introduction

Symptoms:

Issue is observed when the following conditions are met:

• Layer 2 Bridging is used for Lift-and-Shift Migration from NSX-v to NSX-T
• Using NSX-T Federation with global segments
• The Gateway Connectivity option inside of the NSX-T Global segment has been disabled
• NSX-v is the Default Gateway of the VMs for that segment

Loss of connectivity occurs as follows:

• The segment does not know which is the L2-Forwarder Edge node for the RTEP
• NSX-V VMs can talk to NSX-T Site-A VMs
• NSX-V VMs cannot talk to NSX-T Site-B VMs
• VMs at NSX-T site-A cannot talk to VMs at NSX-T Site-B

 

Topology:

 

Environment

VMware NSX-T Data Center

Cause

When the Gateway Connectivity option is disabled, this also disables the cross-location GM_Stretched-Segment communication (VMs at NSX-T site-A cannot communicate to VMs at NSX-T Site-B).

Resolution

This behavior of NSX-T Federation will be changed in a future release of NSX.

Workaround:

Disable the default gateway on NSX-v instead of NSX-T

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-T environment, connect the bridged overlay segment to the tier-1 gateway.
   1. In Global 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.

Additional Information

Bridging a Federated Segment for the Migration:

https://docs.vmware.com/en/VMware-NSX-T-Data-Center/3.2/migration/GUID-AC7335D9-C475-4003-A379-749968428955.html

 

Features and Configurations Supported in NSX Federation:

https://docs.vmware.com/en/VMware-NSX-T-Data-Center/3.2/administration/GUID-29998FC5-C1AB-40BC-B669-6E8E9937F345.html