When vCenter VMs are deployed by vCommander, the MAC addresses are set to manual, even if the base image was originally configured for automatic. This is necessary to provide MAC information to vCommander at the time of deployment. The MAC information is required to achieve other requested network configurations, such as assigning IP addresses from pools, or creating routes for VMs deployed behind a network fence. When vCommander switches a VM’s NIC settings to manual, a unique MAC address is generated, so no MAC collisions are introduced onto the network. This also occurs when vCommander clones VMs previously deployed by vCommander.
However, if you clone a VM deployed or cloned by vCommander directly in vCenter, you will get an exact copy of the VM, including the manually configured MAC address, thereby introducing a conflict onto the network. Avoid working outside vCommander to prevent this from occurring, or reconfigure VMs that have been cloned outside vCommander to use automatic addressing.