AWS Networking for Data Scientists: The VPC

The AWS cloud opens a whole new level of frustration for data scientists. You now have access to a cornucopia of amazing tools, but one big bad ugly stands in the way: The Network!

I find the most frustrating part of a data project is configuring the network. In this post, I am going to review some basic VPC principles.

VPC CIDR blocks are blocks of IP addresses that you can allocate. Most examples show allocated the 10.192.0.0/16 CIDR block or the range that represents 256*256=65536 addresses. Likely far more IP addresses than you will ever need.

Better to use the 10.192.0.0/24 block which allocates 256 IP addresses and divide that up into blocks of 128 addresses using the /25 notation. Note that in AWS a 128 block range will give you 117 usable IP addresses.

VpcCIDR:
  Description: The IP range (CIDR notation) for this VPC
  Type: String
  Default: 10.192.10.0/24

PrivateSubnet1CIDR:
  Description: The IP range (CIDR notation) for the private subnet in the first Availability Zone
  Type: String
  Default: 10.192.10.0/25

PrivateSubnet2CIDR:
  Description: The IP range (CIDR notation) for the private subnet in the second Availability Zone
  Type: String
  Default: 10.192.10.128/25