Computer Networking for Developers: Understand TCP/IP, DNS, HTTP, Routing, and Real World Network Failures

Why can perfectly good application code fail simply because one part of the network path behaves differently than expected?A request that looks like a single function call may depend on DNS resolution, IP addressing, routing, TCP or QUIC, TLS negotiation, proxies, load balancers, cloud networks, containers, timeouts, retries, and remote services. When one layer fails, the application often reports only a vague symptom: timeout, reset, certificate error, 502 response, intermittent connection, or unexplained latency.Computer Networking for Developers gives software developers a practical mental model for understanding what actually happens between one process and another-and for finding failures without treating the network as a mysterious black box.Corin Halstead follows the real path of an application request from hostname to remote service. You will learn how IP addresses, CIDR prefixes, routes, ports, sockets, NAT, IPv4 and IPv6, TCP, UDP, QUIC, DNS, HTTP, and TLS work together and how their responsibilities differ.The book moves beyond protocol definitions to explain the problems developers encounter in production: connection refusals and timeouts, stale DNS answers, broken IPv6 paths, MTU failures, TCP resets, exhausted ephemeral ports, certificate validation problems, proxy and load-balancer errors, connection-pool saturation, retry storms, container localhost mistakes, cloud routing differences, service discovery failures, and intermittent multi-region incidents.You will also learn how modern infrastructure changes the request path. Dedicated chapters examine reverse proxies, CDNs, API gateways, service meshes, cloud networking, Kubernetes, network policies, hybrid connectivity, workload identity, and application security.More importantly, the book develops a repeatable troubleshooting method. Instead of immediately changing code, you will learn to identify the exact endpoint, inspect DNS results, determine the selected address, examine routes, establish whether transport succeeds, verify TLS, follow the application protocol, compare healthy and failing environments, and correlate logs, traces, socket state, flow logs, and packet captures.Practical case studies, diagnostic tables, command-line tools, production-readiness checklists, security guidance, a further-learning path, and a developer networking quick reference turn these concepts into skills you can use under real operational pressure.Whether you build APIs, cloud services, containerized applications, distributed systems, or web platforms, Computer Networking for Developers will help you understand where a request went, what happened along the way, and which evidence tells you what failed.