Examtopics

. Legacy (non-subnetwork) mode is the original approach for networks, where IP address allocation occurs at the global network level. This means the network address space spans across all regions. You can still create a legacy network, but subnetworks are the preferred approach and default behavior going forward. . Subnet mode is the new form of networks in which your network is subdivided into regional subnetworks. Each subnetwork controls the IP address range used for instances that are allocated to that subnetwork. The IP ranges of the different subnetworks in a network might be non-contiguous. There are two options for using subnetworks: .Auto subnet network automatically assigns a subnetwork IP prefix range to each region in your network. The instances created in a zone in a specific region in your network get assigned an IP allocated from the regional subnetwork range. The default network for a new project is an auto subnet network. .Custom subnet network allows you to manually define subnetwork prefixes for each region in your network. There can be zero, one, or several subnetwork prefixes created per region for a network. In order to create an instance in a zone, you must have previously created at least one subnetwork in that region. At instance creation time, you will need to specify the subnetwork in the region that the instance IP should be allocated from. Reference: https://cloud.google.com/compute/docs/subnetworks