VXLAN Standard ping test fails in NSX Logical Switch

Products

• VMware NSX
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• When navigating to vCenter Web Client - Network & Security - Logical Switches, and choosing Logical Switch - Monitor - Ping, VXLAN standard test would fail.
• But if we run ping ++netstack=vxlan -I vmkX -d -s 1572 #.#.#.# in ESXi host command line,  it shows successful.

Environment

VMware NSX for vSphere 6.3.x
VMware NSX for vSphere 6.4.x
VMware vSphere ESXi 6.5

Cause

The VXLAN standard test in UI will create a debug packet that is handled differently than common packet.
Debug packets are being dropped in ESXi 6.5 because they are being handled differently by the platform.

Resolution

This is a known issue on NSX-V 6.4.0 and NSX-V 6.3.6 combined with ESXi 6.5, and only happens to Unicast Replication mode.

Issue has been fixed in NSX-V 6.4.1.