Avoiding Network Identity Collisions after Instant Clone Operations

To avoid a network conflict between a source virtual machine and its instant clone, you must disable at least one of the two conflicting virtual NICs until you complete network customization in the guest operating system of the instant clone. Here are some common approaches:

If the source virtual machine is frozen, its virtual NIC is effectively disabled, and you can reconfigure the guest network settings of the instant clone at any time before the source virtual machine is thawed.

If you derive the instant clone from the current running point of the source virtual machine, you can set the connected property of the virtual NIC backing to false, which disables it in the source before you start the instant clone operation. Then you re-enable the virtual NIC after the instant clone operation completes. After you customize the network settings in the guest operating system of the instant clone, you must re-enable the virtual NIC in the instant clone as well. This approach requires that you tolerate a network interruption until the instant clone operation is complete.

To avoid a network interruption, you can issue the instant clone operation with an InstantCloneSpec that specifies that the virtual NIC in the instant clone will be disconnected. The virtual NIC in the source virtual machine is not affected. After you complete guest operating system customization in the instant clone, you set the connected property of its virtual NIC back to true, and the instant clone operates under its new network identity.

In any case where you change the network identity settings in the guest operating system of the instant clone, you must reset the network stack for the virtual NIC to cause it to adopt the new settings. You can do this by invoking the VirtalMachineGuestCustomizationManager.StartGuestNetwork_Task method after you customize the clone's network settings, or you do the reset from the guest operating system, as with a physical machine. For more information, see Restarting the Guest Network After Customization and Resetting the Network Stack in a Virtual Machine.