The NSX Manager communicates with NSX Edge through the VIX or Message Bus. It is chosen by the NSX Manager when the Edge is deployed and never changes.

Note: VIX is not supported in NSX 6.3.0 and later.
VIX
  • VIX is used for NSX Edge if the ESXi host is not prepared.
  • The NSX Manager gets host credentials from the vCenter Server to connect to the ESXi host first.
  • The NSX Manager uses the Edge credentials to log in to the Edge appliance.
  • The vmtoolsd process on the Edge handles the VIX communication.

VIX failures occur because of:

  • The NSX Manager cannot communicate with the vCenter Server.
  • The NSX Manager cannot communicate with the ESXi hosts.
  • There are NSX Manager internal issues.
  • There are Edge internal issues.

VIX Debugging

Check for VIX errors VIX_E_<error> in the NSX Manager logs to narrow down the cause. Look for errors similar to:
Vix Command 1126400 failed, reason com.vmware.vshield.edge.exception.VixException: vShield 
Edge:10013:Error code 'VIX_E_FILE_NOT_FOUND' was returned by VIX API.:null

Health check failed for edge  edge-13 VM vm-5025 reason: 
com.vmware.vshield.edge.exception.VixException: vShield Edge:10013:Error code 
'VIX_E_VM_NOT_RUNNING' was returned by VIX API.:null

In general, if the same failure occurs for many Edges at the same time, the issue is not on the Edge side.