Networking Basics for Cloud Architects

In cloud projects, networking is the backbone that connects services, people, and partners. A clear network design helps apps scale, keeps data safer, and makes troubleshooting easier. This article covers the core ideas every cloud architect should know, from how addresses are planned to how to connect networks securely.

Key building blocks

These are the main parts you will use in most cloud networks:

  • Virtual networks (VPCs or VNets)
  • Subnets and segmentation
  • Route tables and gateways
  • NAT and outbound access
  • Firewall rules and security groups
  • Load balancers and DNS
  • IP addressing with CIDR
  • Private connectivity (VPN, ExpressRoute, Direct Connect)
  • Peering and shared networks
  • Observability: logs and metrics

A simple pattern

A common pattern is three tiers: public web in a front subnet, private app in a middle subnet, and a private data subnet. The web server talks to the app, and the app talks to the database. The public subnet uses an Internet gateway; the private subnets stay hidden from the Internet. Outbound connections from private subnets go through a NAT device or NAT gateway so servers can reach external services without exposing themselves.

Design tips for cloud architects

  • Start with a solid CIDR plan that avoids overlap
  • Use at least two Availability Zones for resilience
  • Enforce least-privilege rules on firewalls and security groups
  • Separate environments (dev, test, prod) with distinct networks
  • Encrypt data in transit (TLS) and at rest; rotate keys
  • Tag resources for cost control and governance
  • Enable observability: VPC flow logs, DNS queries, health checks
  • Prefer private connectivity (private links) over public endpoints when possible
  • Review changes with a clear change management process

Common pitfalls

  • Overlapping or oversized CIDRs that limit growth
  • Exposing databases or admin consoles to the public Internet
  • Complex routing with many peering links
  • Missing access controls on admin networks
  • Relying on a single NAT or gateway without redundancy
  • Inconsistent tagging and monitoring across environments

Putting it together

Good network design is iterative. Start small, test connectivity end-to-end, and document decisions. As workloads grow, revisit CIDR blocks, security rules, and monitoring to keep the network safe and reliable.

Key Takeaways

  • Plan with CIDR and segmentation to support growth
  • Use private connectivity and controlled access to improve security
  • Monitor, log, and review network rules regularly