Workaround to resolve MAC address mismatch error during guest customization with more than one NIC

Products

• VMware vCenter Server
• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Guest OS Customization fails when setting MAC addresses with more than one NIC in the customization specification.
• The below error is visible in the vCenter Server logs file /var/log/vmware/vpxd/vpxd.log

2022-05-21T16:57:58.294Z error vpxd[06167] [Originator@6876 sub=VmCustomizer opID=5af2c1a7-02] MAC Address mismatch: specMAC=00:50:xx:88:0d:b1 , vmMAC=00:50:xx:88:34:e0
 

Environment

VMware vSphere ESXi 8.0.x
VMware vSphere ESXi 7.0.x

Cause

This issue occurs when the mac addresses in the customization spec are not set in the ascending order of pciSlotNumber, maybe it follows the order of network adapters in the 'Edit Setting'.

Resolution

This is applicable in below VC versions:
VC7.0P02(7.0 U1c)
7.0U1d GA
VC 7.0U2
VC 7.0 P03
VC 7.0U3

The issue has been resolved in VC 8.0 GA.
So no need to apply this work around in VC 8.0 GA or later VC versions.

Workaround:
When creating the customization specification, the mac addresses should be set in the ascending order of pciSlotNumber. The values of pciSlotNumber can be found from the .vmx file as in the below example.
 

ethernet0.generatedAddress = "00:50:xx:82:c1:d4"
ethernet0.pciSlotNumber = "192"
ethernet1.generatedAddress = "00:50:xx:82:11:73"
ethernet1.pciSlotNumber = "34"

If the ethernet0.pciSlotNumber > ethernet1.pciSlotNumber, 
it needs to set the  mac address of ethernet1 first and then set the mac address of ethernet0 in the customization spec.