NSX multiple overlay transport zone configuration in a Host Transport Node in NSX 4.X and onwards is not allowed

Products

• VMware NSX

Issue/Introduction

You see an error similar to the following when configuring an ESXi host transport node with multiple overlay transport zones:

HostSwitch <HostSwitch ID> cannot participate in more than one OVERLAY transport zone, existing TZ [<existing TZ ID>] new TZ [<new TZ ID>]. (Error code: 9503)

Environment

VMware NSX 4.x

Cause

Using multiple overlay transport zones on an ESXi host transport node has never been supported. The check for this condition was not added until the 4.x version of VMware NSX.
Only one vdl2 instance is created per HostSwitch so it can span over only one Overlay Transport Zone.

 

Resolution

Not supported configuration

Additional Information

You may see that you are able to configure an ESXi host transport node with multiple overlay transport zones in VMware NSX-T Data Center 3.x as the check for this condition is not present. This is still an unsupported configuration and must not be used.

 

The HostSwitch can still span over multiple VLAN Transport Zones.