NSX Edge VM Hard Limit of 4 Data Network IDs

Products

• VMware NSX

Issue/Introduction

When deploying an NSX Edge VM Appliance, the deployment configuration is restricted by a hard limit of 4 data_network_ids (vNICs) under the VM deployment settings. Attempting to assign more than this limit results in a deployment failure.

Environment

VMware NSX 

Cause

The NSX Edge VM Appliance architecture includes a strictly enforced hard limit of 4 data_network_ids per appliance. This design constraint ensures consistent datapath performance and simplifies the appliance's network stack. There is no configuration change or hidden setting to bypass this limit.

Resolution

To connect the Edge VM to 5 or more distinct networks, use 802.1Q VLAN trunking to multiple networks over a reduced number of datapath interfaces.

1. Configure Trunk Port Groups on the vSphere Distributed Switch (VDS). Set the VLAN type to "VLAN trunking" and specify the required VLAN range.
2. During the Edge VM deployment, assign 2 to 4 data_network_ids to these trunked Port Groups.
3. Within NSX Manager, create VLAN-backed Segments for every individual network required (e.g., TEP VLANs, BGP Peering VLANs).
4. Utilize Named Teaming Policies within the Edge Uplink Profile to control traffic flow (e.g., forcing specific BGP traffic out of a designated interface).

By trunking multiple VLANs into the standard data interfaces, the Edge appliance handles VLAN tagging internally, allowing the routing of dozens of networks through the supported 2- 4 datapath interfaces without exceeding the vNIC limitation.

Additional Information

For more details on deploying Edge Transport Nodes, see Create an Edge Transport Node.