T0 A/A Stateful traffic flow disruption

Products

• VMware NSX

Issue/Introduction

Symptoms:

• NSX 4.x
• T0 Gateway configured for stateful Active/Active.
• Traffic traverses the Edge, entering on an Uplink interface and exiting an Uplink interface.
• This Uplink to Uplink traffic experiences packet loss and disruption.
• Standard North/South traffic flows are not impacted.

Environment

VMware NSX-T Data Center

Cause

T0 A/A stateful configuration does not support Uplink to Uplink traffic flows.

Resolution

This is known behaviour on NSX 4.x.

Workaround:
When traffic traverses an Edge ingressing on an Uplink and egressing on an Uplink, stateful A/A is not supported.

To workaround this issue configure stateful Active/Standby to avoid traffic disruption.

Note: once A/A stateful is configured it cannot be reverted to A/A stateless so A/S must be used as a workaround.