NSX ARP Snooping Ignores the APIPA (IPv4 Link-Local) Range 169.254.x.x

Products

• VMware NSX

Issue/Introduction

• An NSX Segments IP Discovery Profile is configured with ARP Snooping enabled.
• One or more VMs associated with the above segment are configured with IPs in the APIPA (IPv4 Link-Local) range 169.254.x.x.
• ARP Snooping address bindings in the APIPA (IPv4 Link-Local) range 169.254.x.x are not discovered by NSX.

Environment

VMware NSX

Cause

ARP Snooping operates at the data plane by inspecting network traffic.  NSX ARP Snooping ignores APIPA IPs by design because APIPA IPs are often transitory to ensure that only "intended", routable IPs populate the NSX discovery tables.  

NB: VMware Tools operates inside the Guest OS and discovers all active IPs (APIPA and Routable) in the default VM namespace.

Resolution

This is a condition that may occur in a VMware NSX environment.

Workaround
Enable VMware Tools for the relevant IP Disovery Segment Profile(s) to allow the Guest OS of segment VMs to discovers all active IPs (APIPA and Routable) in the default VM namespace :
NSX UI:  Networking > Segments > Profiles > Edit the relevant IP Disovery Segment Profile(s) > Enable VMware Tools