vMotion of a Virtual Machine fails when multiple vmnics on ESXi hosts are directly connected to each other without a Physical Switch

Products

• VMware vSphere ESXi
• VMware vCenter Server

Issue/Introduction

• vMotion of the Virtual Machine fails with following error:

The vMotion failed because the destination host did not receive data from the source host on the vMotion network. Please check the vMotion network setting and physical network configuration and ensure they are correct.

• Source and destination ESXi hosts are directly connected to each other without a Physical Switch.
• All uplinks in Teaming for Portgroup where vMotion VMkernel adapter resides are in Active state.
• vmkping over vMotion network is unsuccessfull.

Environment

VMware vCenter Server

VMware vSphere ESXi

Cause

ESXi hosts are physically connected to each other in following fashion:

Since vmnic0 and vmnic1 are in Active-Active state for teaming of the portgroup where vMotion VMkernel adapter resides, vMotion vmk can use either vmnic0 or vmnic1 to pass the traffic.

Let's say vmk1 is designated for vMotion traffic on both of the ESXi hosts. vmkpings will fail in following scenario's:

ESXi host 1 -> vmk1 -> vmnic0
ESXi host 2 -> vmk1 -> vmnic1

OR

ESXi host 1 -> vmk1 -> vmnic1
ESXi host 2 -> vmk1 -> vmnic0

The reason is because traffic sent from ESXi host 1 over vmnic0 will be received only on vmnic0 present on ESXi host 2 as they are directly attached. Same goes for vmnic1.

Resolution

Change the teaming policy of Portgroup for vMotion VMkernel adapter such that only single Network adapter is in active state.

Active : vmnic0
Standby: vmnic1

OR

Active : vmnic1
Standby : vmnic0