**AWS CloudFront is a CDN with 13+ Regional Edge Caches and 400+ Edge locations.
*44. Defining VPC CIDR Blocks
**8 host bits = 256 addresses /24 subnet mask 255.255.255.0
**16 host bits = 65,536 addresses /16 subnet mask 255.255.0.0
**12 host bits = 4096 addresses /20 subnet mask <ref>https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing#IPv4_CIDR_blocks</ref>
**Cannot increase or decrease the size of your CIDR block once it's defined (You'd have to create and migrate to a new VPC)
**Recommended to use RFC 1918 ranges <ref>The Internet Assigned Numbers Authority (IANA) has reserved the
following three blocks of the IP address space for private internets:
10.0.0.0 - 10.255.255.255 (10/8 prefix)
172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
192.168.0.0 - 192.168.255.255 (192.168/16 prefix)
We will refer to the first block as "24-bit block", the second as
"20-bit block", and to the third as "16-bit" block. Note that (in
pre-CIDR notation) the first block is nothing but a single class A
network number, while the second block is a set of 16 contiguous
class B network numbers, and third block is a set of 256 contiguous
class C network numbers.</ref>
**https://docs.aws.amazon.com/vpc/latest/userguide/subnet-sizing.html
**Solarwinds has an interactive (not obvious) calculator https://www.solarwinds.com/free-tools/advanced-subnet-calculator
*45. [HOL] Create a Custom VPC
*46. VPC Routing Deep Dive
*55. VPC Endpoints
*56. [HOL] Create VPC Endpoint
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