Cloud Networking Essentials for Developers

Cloud networking is foundational for reliable and secure applications. Developers should understand the primitives (VPCs, subnets, routing, security groups), load balancing options, DNS, and hybrid connectivity (VPN, Direct Connect/Interconnect) to design safe architectures.

VPCs, subnets, and address planning

• Choose CIDR ranges to avoid conflicts with on-prem networks when planning VPNs.
• Use private subnets for databases and internal services; public subnets for NAT or load balancers.

Security groups and firewall rules

• Security groups are stateful; network ACLs can provide stateless filtering.
• Default-deny inbound and explicit allow for application ports.

Load balancing and ingress

• Use managed load balancers (ALB, NLB, Cloud Load Balancing) for high availability.
• Terminate TLS at the edge with certificate management via managed certs or ACM.

DNS and service discovery

• Use cloud DNS for public zones and private DNS for internal service discovery.
• For microservices, consider service meshes or DNS SRV records for discovery.

Hybrid connectivity

• VPN: lower cost, higher latency; good for dev/test.
• Direct Connect / Interconnect: private link with predictable performance for production.

Network performance and observability

• Monitor packet drops, latency, and bandwidth. Use VPC Flow Logs for traffic analysis.

Common developer mistakes

• Exposing databases publicly during development.
• Using overlapping CIDR ranges without planning.

Internal links

• Pillar: Practical Cloud Computing for Developers
• Related: Getting Started with AWS for Developers
• Related: Infrastructure as Code with Terraform

External references

• AWS VPC overview: https://docs.aws.amazon.com/vpc/
• Google Cloud VPC: https://cloud.google.com/vpc
• Azure Virtual Network: https://learn.microsoft.com/azure/virtual-network/