It’s been a month since NSX 6.3 has been released. It just came to my attention that an unknown behaviour of the NSX-Controller has been changed with that release.
We have 3 NSX-Controller while 2 of them should at least be available to remain complete functional. As we all hopefully now the NSX-Controller manages tables (VTEP, MAC, ARP) for Layer-2 VXLAN Operations (if we have selected hybrid or unicast as a replication mode).
NSX-Controller Failure
The following tables tries to explain the impact of controller failures in case we are in Unicast or Hybrid-Mode in case of Layer-2 switching functionality:
| NSX Controller Available | Cluster-Status | NSX-Controller Operations Mode | Impact |
| 3 | healthy | read/write | No Impact |
| 2 | degraded | read/write | No Impact |
| 1 | degraded | read only | New VMs or vMotioned VMs will have networking issues |
| 0 | headless(-chicken) | – | New VMs or vMotioned VMs will have networking issues |