MAC prefix parameters are invalid

Products

• VMware vCenter Server

Issue/Introduction

vCenter VM will not power on

Errors in the /var/log/vmware/vpxd/vpxd.log similar to:

2026-08-21T14:41:11.273Z error vpxd[205047] [Originator@6876 sub=InvtId] MAC prefix parameters are invalid: range [xxxxxxxxxxx, xxxxxxxxxx]  overlaps with VMware reserved MAC ranges

2026-08-21T14:41:11.273Z error vpxd[205047] [Originator@6876 sub=InvtId] Failed to get MAC alloc scheme parameters from vpxd.cfg

2026-08-21T14:41:11.273Z error vpxd[205047] [Originator@6876 sub=Main] Init failed.

Checking the  <macAllocScheme> in the vpxd.cfg file, a different prefix and range from the error is shown

 <macAllocScheme>

   <prefixScheme>

   <prefix>xxxxxxxxxxx</prefix>

   <prefixLength>xxxxxxxxxxx</prefixLength>

   </prefixScheme>

  </macAllocScheme>

Environment

vCenter 8.x 

vCenter 9.x

Cause

The values for <macAllocScheme> are usually set during the deployment of the vCenter (see kb 443798).  If these values have somehow been changed or the file has somehow become corrupted then you may get the error listed.

Resolution

1.  Login to the command line of the vCenter

2.  Backup the vpxd.cfg file

3.  Edit the vpxd.cfg file to remove the tags 

 <prefix>xxxxxxxxxxx</prefix>

   <prefixLength>xxxxxxxxxxx</prefixLength>

4.  Then carefully type the tags back in manually (matching the in xml indentation) with the needed values.

5.  Try to start the vCenter Services from the command line:  service-control  --start --all