Cloud Networking & Security — Overview

What it is, why it matters, architecture and key concepts

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Written by senior engineers. Reviewed for technical accuracy.· Updated 2025 · SynfraCore Cloud Networking & Security Team

Expert Content

Cloud Networking and Security — Overview

Why Networking and Security are Inseparable

Every cloud resource exists inside a network. Network design determines what can talk to what. Security determines who can talk and whether data is encrypted. Both must be designed together from day one.

AWS Networking

VPC Structure

VPC: 10.0.0.0/16
Public Subnet  → Internet Gateway (internet access)
Private Subnet → NAT Gateway (outbound only)
Database Subnet → No internet access

Security Groups vs NACLs

Feature	Security Groups	Network ACLs

|---------|----------------|-------------|

Stateful	Yes	No
Scope	Per instance	Per subnet
Return traffic	Automatic	Must allow explicitly

VPC Connectivity

Need	Solution

|------|---------|

VPC to VPC same account	VPC Peering
Multi-account networking	Transit Gateway
On-premises (dedicated)	AWS Direct Connect
Private access to AWS services	VPC Endpoints

Azure Networking

VNet Structure

VNet: 10.1.0.0/16
Frontend Subnet → NSG (web tier)
Backend Subnet  → NSG (app tier)
Database Subnet → NSG + Private Endpoints

NSG vs Azure Firewall

Feature	NSG	Azure Firewall

|---------|-----|---------------|

Layer	L4	L4 + L7
FQDN filtering	No	Yes
Cost	Free	Paid (~$1.25/hour)

Zero Trust Principles

1.Verify identity explicitly — MFA, device health check, location

2.Least privilege access — RBAC, just-in-time access

3.Assume breach — segment everything, monitor all traffic

Encryption Checklist

•Storage: AES-256 encryption at rest (S3, RDS, EBS, Blob Storage)

•Transit: TLS 1.2+ enforced everywhere

•Secrets: AWS Secrets Manager or Azure Key Vault — never environment variables

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