Free tutorial · 28 lessons
Networking Tutorial
Computer networking for developers and cloud engineers: IP addresses, subnets and CIDR, IPv6, ports, TCP, UDP, DNS, HTTP, TLS, routing, NAT, firewalls, load balancers and CDNs, then cloud networks on AWS with Azure and Google Cloud equivalents. Every example is a short Python program you can run in the browser.
Networking Basics
- Networking Introduction — What computer networking is, why every developer and cloud engineer needs it, and what this tutorial covers.
- How the Internet Works — Packets, routers, and the trip a request takes from your browser to a server and back.
- OSI and TCP/IP Models — The layer models engineers use to describe networks, and what lives at each layer.
- IP Addresses (IPv4) — How IPv4 addresses are written, public versus private ranges, and special addresses you'll meet in the cloud.
- Subnets and CIDR — Read CIDR notation like 10.0.0.0/16, calculate how many addresses a subnet holds, and split a network into subnets.
- IPv6 — Why IPv6 exists, how its addresses are written and shortened, and how it is used in cloud networks.
- Ports and Sockets — How one machine runs many network services at once: ports, sockets, and the 5-tuple that identifies a connection.
- Internet Protocols: History & Versions — How the ARPANET became the internet, the standards behind TCP/IP, DNS, HTTP and TLS, every major protocol version on one timeline, and which versions to use and support today.
Core Protocols
- TCP — How TCP delivers a reliable, ordered byte stream: the three-way handshake, acknowledgements, and closing connections.
- UDP — UDP's fire-and-forget datagrams, when they beat TCP, and the protocols built on them (DNS, QUIC, video, games).
- DNS — How a name like www.example.com becomes an IP address: resolvers, the DNS hierarchy, caching and TTLs.
- DNS Record Types — A, AAAA, CNAME, MX, TXT, NS and the cloud's alias records: what each one is for, with examples.
- HTTP — The request/response protocol of the web: methods, status codes, headers, and what an HTTP message looks like.
- HTTPS and TLS — How TLS encrypts connections and proves a server's identity with certificates, and the errors you'll meet.
- HTTP/1.1, HTTP/2 and HTTP/3 — What changed between HTTP versions, why HTTP/2 multiplexes and HTTP/3 runs over QUIC, and what it means for your app.
Routing and Network Services
- Routing and Gateways — How routers and route tables decide where packets go: longest-prefix match, default routes and gateways.
- NAT — How network address translation lets many private hosts share public addresses, and its limits.
- Firewalls — Stateful and stateless firewalls, allow and deny rules, and why return traffic needs ephemeral ports.
- Load Balancers — Layer 4 and layer 7 load balancers, balancing algorithms, health checks and the timeouts that cause 502s.
- Proxies and CDNs — Forward and reverse proxies, CDNs and edge caching, and the headers that carry the real client IP.
- Network Troubleshooting — A step-by-step method and the commands (dig, ping, traceroute, nc, curl, ss, tcpdump) to find why a connection fails.
Cloud Networking
- Virtual Private Clouds (VPC) — What a VPC is, how to choose its address range, and how AWS VPCs compare with Azure VNets and Google Cloud VPCs.
- Public and Private Subnets — Build the classic layout: public subnets with an internet gateway, private subnets with a NAT gateway, across availability zones.
- Security Groups and Network ACLs — Control traffic in a cloud network with stateful security groups and stateless network ACLs, and design rules by tier.
- Connecting Networks — Connect VPCs to each other and to on-premises networks: peering, transit gateways, VPNs and dedicated links.
- Private Access to Cloud Services — Reach S3, databases and SaaS APIs without the internet using gateway endpoints, PrivateLink and private endpoints.
- DNS in the Cloud — Public and private hosted zones, the VPC resolver, split-horizon DNS and resolving names between cloud and on-premises.
- Networking Next Steps — What to learn next: the Cloud Networking in Production course, the networking quiz, interview questions and Terraform.