Virtual machine MAC address changes and ARPs will not be acknowledged.

Products

• VMware vSphere ESXi

Issue/Introduction

- Virtual machine MAC address changes automatically.

- ARPs will not be acknowledged for the VNICs.

- If the virtual machines are in clustering they might even reboot without much evidence from the logs.

- The MAC address from the Port group and the Appliance/VM do not match.

- The VMware.log of the VM will have a different MAC at the start of the VM from what we see from the Port group.

Environment

6.x and above.

Cause

The MAC address change has been set to Reject in the security policy of the distributed port group setting.

Resolution

Update the MAC address changes to Accept in the security policy of the DVS to which the VMs are attached so that the ARPs are acknowledged and the packets are not dropped.

 

Additional Information

https://techdocs.broadcom.com/us/en/vmware-cis/vsphere/vsphere/7-0/vsphere-networking-7-0/networking-policies/security-policy/configure-the-security-policy-for-a-distributed-port-group-or-port.html