Problem scenario
You run an AWS CLI command. But you get this message:
An error occurred (InsufficientFreeAddressSpaceInVpc) when calling the CreateDefaultSubnet operation: The VPC 'vpc-123abcd' does not have enough free address space to allocate an additional /20 subnet.
How do you troubleshoot this AWS CLI error?
Solution
Go to the VPC section of AWS. Find the VPC in the error and click on it. Go to "Edit CIDRs" and add a CIDR to allocate more IP addresses.