Edge VM packet loss limitations

Products

• VMware NSX

Issue/Introduction

Even in perfect conditions with low CPU usage (<50%) on the Edge Virtual Machine, an NSX Edge Virtual Machine cannot achieve receive rate packet loss of less than 0.001%.

Calculating receive rate loss:

Edge> get physical-port fp-eth1 stats

Physical Port Stats
NAME              : fp-eth1
RX_BYTES          : 2992669382
RX_ERRORS         : 0
RX_MISSES         : 25296
RX_NOMBUFS        : 0
RX_PACKETS        : 3613777910
TX_BYTES          : 1288975412
TX_DROPS          : 0
TX_ERRORS         : 0
TX_PACKETS        : 13924459



(25296/3613777910) x 100 = 0.0007%

Environment

VMware NSX-T 3.x
VMware NSX 4.x

Cause

This is due to the fundamental nature of the Edge being a virtualized entity on shared infrastructure and the requirement to be scheduled on ESXi CPUs.

Resolution

If there is a requirement for the environment to achieve sub 0.001% packet loss, Broadcom recommends to deploy a Bare Metal Edge.