From the feature matrix and the required features, the only options left around the VirtualBox networking are NAT Network and Bridged Networking. The problem with the Bridged networking is that as mentioned above, it always requires connection to the network and switching to a different network changes the IP of the K8S master and breaks down the entire setup. The certificates during the K8S setup are tied to a specific IP and need to generated again each time the IP address of the master changes (1). This is not impossible, but is tedious every time we change the network and the IP address of the master changes. So, the only optimal option left is to use the NAT Network.
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