CVDS behaviour regarding MAC learning feature on NSX Segment profiles

Products

• VMware NSX
• VMware vSphere ESXi 8.0

Issue/Introduction

You may see that with the command 

nsxdp-cli vswitch mac-table get -dvs <CVDS_NAME>

we see that DVS uplinks have the MAC LEARNING  enabled even  with Only one VLAN segment having the  MAC Discovery. segment profile with the MAC Learning feature enabled 

from the following command we see  both Static and Learned  MACs
nsxdp-cli vswitch mac-learning all-ports get -dvs <CVDS_NAME>



conversely, with MAC learning disabled on all the segments of type VLAN you have the following output: 

nsxdp-cli vswitch mac-learning all-ports get -dvs <CVDS_NAME>

No Learning at all 

nsxdp-cli vswitch mac-table get -dvs <CVDS_NAME>
We see only static MAC entries 

Environment

NSX with Converged DVS (CVDS)

Resolution

This is expected behaviour, the following KB is for clarifying that even one segment with MAC discovery profile with MAC learning enabled you can have MAC entries learned on the uplinks, and this is a guide to clarify this behaviour in term of switching equipment that could be impacted by this issue.