North-South Performance issue when NSX T1 gateway configured with edge cluster in large environment

Products

• VMware NSX

Issue/Introduction

• VMs in NSX overlay segment are having performance issues(latency increase or packet drop) in North - South communication.
• Large traffic under single T1 gateway.
• T1 gateway HA mode is Active-Active or Active-Standby.
• Physical switch flow graph may show interface utilization near 100% for Edge hosting T1 gateway corresponding interface.

Environment

VMware NSX

Cause

Centralized north to south edge configuration introduced latency in physical switch.

Resolution

• Confirm no stateful services (LB/NAT/Firewall) in use in T1 gateway.
• Change T1 gateway with large traffic HA mode to distributed only.
• This helps redistrbuting traffic to all edges where T0 gateway resides thus enhancing physical switch performance.