When changing the MAC address of a virtual machine from Manual to Automatic, 00:0C:29x:x: is set instead of 00:50:56x:x:
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Article ID: 316642
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Updated On:
Products
VMware vCenter Server
Issue/Introduction
When changing the MAC address of a virtual machine from Manual to Automatic, 00:0C:29x:x: is set instead of 00:50:56x:x:
Environment
VMware vCenter Server 8.0.x VMware vCenter Server 7.0.3
Cause
The 00:0c:29:xx:xx:xx MAC address is generated by the host, not by the vCenter.
When the user change the MAC address from static to automatic , vCenter doesn't capture that configuration change thus it doesn't generate the MAC address for it.
When the VM gets powered on, host checks if a MAC has been generated in the case the MAC address is set to automatic. In this case, it doesn't find a generated MAC address, thus it generates 00:0c:29 MAC address.
Resolution
Issue is fixed in vCenter 7.0.3 P06 and vCenter 8.0.0.1 P1
Workaround:
Remove and re-add the vNIC of the impacted VM.
Additional Information
Changing MAC type from manual to automatic through vCenter set an unexpected MAC address range of 00:0C:29 instead of 00:50:56