Cloud networking core encompasses the fundamental building blocks of virtual network infrastructure in modern cloud platforms. VPC (Virtual Private Cloud) architecture serves as the isolated network foundation, enabling organizations to design secure, scalable, and highly available network topologies within cloud environments. Understanding CIDR planning, route propagation, and multi-tier segmentation is critical to building production-ready systems that balance security requirements with connectivity needs. Cloud networking differs from traditional on-premises networking in its software-defined nature — gateways, routes, and security policies are configured as code rather than physical hardware, allowing unprecedented flexibility but requiring mastery of new abstractions and gotchas that can silently degrade performance or expose security gaps.
What This Cheat Sheet Covers
This topic spans 19 focused tables and 197 indexed concepts, 169 flashcards. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
A jump-to index of every table row in this cheat sheet.
An interactive map of every table and concept in this topic.
Table 1: VPC Fundamentals
A Virtual Private Cloud is the foundational network boundary in every major cloud provider. Before touching subnets or routes, you must internalize how CIDR blocks, reserved IPs, and VPC-level attributes shape everything that runs inside.
| Concept | Example | Description | |
|---|---|---|---|
10.0.0.0/16172.31.0.0/16 | • Logically isolated virtual network dedicated to your account • defines the IP address space for all resources within it. | ||
10.0.1.0/24 (public)10.0.2.0/24 (private) | • Subdivision of a VPC CIDR block within a single availability zone • resources launch into specific subnets. | ||
/16 = 65,536 IPs/24 = 256 IPs | • Classless Inter-Domain Routing notation defining the IP range • smaller prefix = larger address space. | ||
10.0.0.0/16 | • The initial IPv4 address range assigned when creating a VPC • cannot be modified after creation. | ||
Add 10.1.0.0/16to existing VPC | • Additional IPv4 ranges associated with a VPC to expand address space • up to 5 by default (adjustable to 50). | ||
2600:1f14::/56 | • Global Unicast Address range for IPv6 • AWS assigns a /56 block automatically when enabled. | ||
IPv4 + IPv6 enabled | • VPC configured to support both IPv4 and IPv6 simultaneously • traffic operates independently per protocol. | ||
In 10.0.0.0/24:.0, .1, .2, .3, .255 | • AWS reserves 5 IPs per subnet • .0 = network, .1 = VPC router, .2 = DNS, .3 = future use, last = broadcast. | ||
VPC-A ↔ VPC-B non-transitive | • Direct network connection between two VPCs • traffic uses private IPs without internet gateway; no single point of failure. | ||
Reserve 10.0.1.100/30for prefix delegation | • Reserves a range within a subnet to prevent automatic assignment • useful for container prefix delegation. | ||
enableDnsSupport = true | • VPC setting enabling the Amazon DNS server • required for private hosted zones and PrivateLink. | ||
enableDnsHostnames = true | • VPC setting assigning public DNS names to instances with public IPs • must be enabled alongside DNS support |