4 Replies Latest reply on May 24, 2011 2:24 PM by bedickson

    MAC address OUI confusion

    Vodder Hot Shot

      Hi,

       

      I always thought that MAC addresses assigned by ESX were of the format 00:50:56:XX:XX:XX and still is as confirmed here

       

      http://pubs.vmware.com/vsphere-esxi-4-1-installable/wwhelp/wwhimpl/js/html/wwhelp.htm#href=server_config/c_setting_up_mac_addresses.html

       

      However when trying to hunt down some particular weird happenings on a DC; whilst in the ARP cache I noticed a lot of 00:0c:29:XX:XX:XX addresses. By chance I then noticed these were linked to a group VM's on a stand alone host.

       

      These haven't been manually changed and I was expecting 00:50:56:XX:XX:XX. Googling around I found nothing direct from VMware on this, however I did find a blog that stated the 00:0c:29:XX:XX:XX range is used when a VM is created directly on an ESXi host. Is this true? These VM's were not created directly on any host however they were manually added to the inventory of the standalone host - would this cause this?

       

      In addition the blog also mentioned the OUI 00:05:69 as potentially being used by VMware.

       

      Can any clarify this please?

       

      Thanks.

      Tim