Identify the missing word(s) in the following sentence within the context of Microsoft Azure. For all availability configurations of availability groups (AGs), an underlying cluster is required. There are many aspects of setting up a cluster that you need to be aware of. A typical [?] will only require a single virtual network card (vNIC). The IP address for the vNIC has to be configured in Azure. That means inside the VM it will show up as a dynamic (DHCP) address. This is expected, however cluster validation will generate a warning that can safely be ignored.