NSX edge datapath configuration failure due to KNI port limit exceeded in multi-VRF configuration

Products

• VMware NSX

Issue/Introduction

• Edge datapath configuration is failing to realize on edge node(s).
• Impacted edge node(s) may be unable to pass traffic.
• NSX UI displays 'Edge Datapath Configuration Failure' alarm as described in KB 330461.
• In /var/log/syslog* in the edge logs:
  
  Edge datapath configuration failure:

  <edge-node-name> NSX 1 - [nsx@6876 comp="nsx-edge" subcomp="nsx-edge-agent" s2comp="nsx-monitoring" entId="<Edge-UUID>" tid="1" level="ERROR" eventState="On" eventFeatureName="edge_health" eventSev="error" eventType="edge_datapath_configuration_failure"] Context report: {"reason":""}

  
  Failed to create KNI port:
  

  <edge-node-name> NSX 5114 FABRIC [nsx@6876 comp="nsx-edge" subcomp="datapathd" s2comp="dpc-pb" tname="dp-ipc19" level="ERROR" errorCode="EDG0400102"] Failed to create kni port trunk-<Port-Number>
  <edge-node-name> e0a46335e73c 3568 - -  2025-04-04T12:48:40Z datapathd 5114 dpc-pb tname="dp-ipc19" [ERROR] Failed to create kni port trunk-<Port-Number>  errorCode="EDG0400102"

Environment

VMware NSX

VMware NSX-T Data Center

 

Cause

In a multi-VRF configuration, the edge KNI port limit of 32 has been exceeded due to the creation of multiple VLAN trunk segments.

NB:  Each VLAN trunk segment requires one trunk router port that is backed by one KNI port on the edge.

 

Resolution

The recommendation for a multi-VRF environment is to configure a single VLAN trunk segment per Tier-0 gateway.  This single VLAN trunk segment should include the VLAN ranges being used for all VRFs associated with the Tier-0 gateway.

 

Workaround

If present, unused VLAN trunk segments associated with the impacted Tier-0 gateway can be deleted or disconnected from the Tier-0 gateway as a workaround.