The default VPC

This network uses 20 bits for the host allocation, and a 12-bit network mask (32-20=/12). The default VPC can be identified because it uses the CIDR address space of 172.31.0.0/16; this kind of network allows for 16 contiguous class B networks, and the following combinations are available:

One big subnet with the full space, with 65,534 hosts, as shown in the following screenshot:

In the VPC, this subnet is usable with 65,531 IPs, as shown in the following screenshot:

This is a poorly designed VPC, because the subnet will use ...

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