This article explains how the PHP curl_multi_getcontent() function works, demonstrates its usage together with curl_multi_init() and curl_multi_exec() for concurrent requests, provides a complete code example, and highlights important considerations when fetching results from multiple cURL handles.
Zephyr RTOS 3.7.0 LTS was released on July 26, 2024, introducing over 650 contributors, new hardware models, expanded POSIX and Bluetooth support, numerous API changes, extensive driver updates, enhanced networking features, and a series of security patches covering multiple CVEs.
This article provides a detailed, step‑by‑step analysis of the go‑libp2p Swarm implementation, covering host creation, configuration defaults, transport registration, server listening, stream multiplexing with yamux, and the client dialing workflow including dial synchronization, backoff handling, and connection pooling.
This article provides a comprehensive overview of Ethernet technology, explaining the roles of MAC and PHY chips, the OSI layer interactions, and the various interfaces such as MII, RMII, GMII, RGMII, and SMI, along with practical hardware integration details.
Learn how to understand IPv6 address types, enable IPv6 support, configure static addresses on Debian/Ubuntu and CentOS/RHEL, verify settings, and test connectivity using Linux commands, with detailed examples and scripts for both global unicast and unique local addresses.
This article explores the history, technical feasibility, vendor support, and real‑world testing of the unused IPv4 Class E address block (240.0.0.0/4), concluding that while it can serve large private networks, widespread adoption is impractical and IPv6 remains the preferred solution.
This guide explains how to enable VLAN tagging on a Linux server, create VLAN interfaces for different subnets, assign IP addresses, and make the configuration persistent on CentOS/RHEL systems using kernel modules, ip commands, and network‑script files.
This article explains the PHP curl_errno() function, shows how to use it to obtain cURL error codes with example code, lists common error numbers, and demonstrates proper error handling to improve application stability.
When running Jenkins inside a Docker container on a VM, HTTPS requests to accounts.google.com time out due to an MTU mismatch between the host and the container, which can be resolved by adjusting the MSS via iptables or setting a lower MTU for Docker interfaces.
While both localhost and 127.0.0.1 point to your local machine, they differ in resolution methods, IPv4/IPv6 handling, performance nuances, and configuration flexibility, making it essential for developers to understand these subtleties for optimal testing, development, and network compatibility.
This article explains the challenges of multi‑cluster deployments and presents three Alibaba Cloud solutions—PrivateLink, Cloud Enterprise Network (CEN), and ASM East‑West Gateway—detailing their mechanisms, trade‑offs, and typical scenarios such as isolation, distributed applications, disaster recovery, and multi‑environment testing.
This article explains how the PHP curl_multi_add_handle() function can add multiple cURL handles to a single multi‑handle session, provides its syntax and parameters, and includes a complete example demonstrating initialization, adding handles, executing requests, retrieving responses, and cleaning up.
This guide explains Linux routing commands for adding host and network routes, setting default gateways, creating permanent static routes via rc.local, sysconfig files, and static‑routes, enabling IP forwarding, and demonstrates a dual‑NIC experiment using VMware and eNSP to achieve simultaneous internal and external network access.
This guide provides a concise collection of OpenStack Nova and Neutron command‑line examples for listing, creating, modifying, and deleting virtual machines, networks, subnets, and related resources, helping administrators efficiently manage cloud infrastructure.
With Kubernetes clusters expanding across multiple environments, choosing the right cross‑cluster networking method is crucial; this article compares six approaches—underlay networks, overlay CNI meshes, Submariner, Skupper, KubeSlice, and others—detailing their core principles, advantages, and limitations to help you select the best fit.
This guide explains what a default gateway is, how to set it manually on Linux, and how to handle single, dual, or triple NIC configurations using route and iproute2 commands, including creating separate routing tables, static routes, and bonding for redundancy and load balancing.
This guide compiles essential Linux command-line techniques, covering port inspection, disk and CPU monitoring, time‑based file cleanup, secure copying with scp, file searching, disk usage analysis, system information retrieval, firewall management, permission changes, and advanced utilities like watch, crontab and mount.
The article recounts a Tencent engineer's six‑year journey from early DNS‑bypass tricks to modern HTTP/2 + QUIC implementations, highlighting technical challenges, security innovations, and the iterative process behind multiple promotion evaluations.
This article explains the subtle distinctions between the hostname localhost and the IPv4 loopback address 127.0.0.1, covering their definitions, resolution processes, performance impact, IPv6 considerations, practical usage scenarios, and best‑practice recommendations.
This article explains how Kubernetes' kube-proxy component implements service discovery and load balancing using two modes—iptables and ipvs—detailing the underlying packet‑processing chains, NAT rules, probability‑based forwarding, and the performance differences between the two approaches.
This article explains the TCP/IP four‑layer architecture, how data is encapsulated and decapsulated across layers, the operation of ARP and DNS protocols, and how sockets provide user‑space access to these networking services.
A Linux client sets SO_SNDBUF to 4096 bytes and sends 1 KB packets while the server never receives them, yet the TCP Send‑Q grows to 14480 bytes, prompting an in‑depth analysis of kernel buffer accounting, double‑sized send buffers, and tcp_sendmsg behavior.
This article explains how Kubernetes assigns unique IP addresses to Pods using Flannel as the CNI network provider and Containerd as the container runtime, covering underlying concepts like Linux bridges, VXLAN encapsulation, node IPAM, and the interactions among kubelet, CRI, and CNI plugins.
This guide provides a comprehensive visual overview of core networking concepts, covering Ethernet frame structure, WLAN standards, structured cabling, network interconnection devices, routing protocols, IP datagram format, private address ranges, TCP/UDP packet formats, common ports, DHCP workflow, Kerberos authentication, SNMP versions, RISC vs CISC differences, RAID technologies, OSI layer functions, and digital transmission standards.
This article explains why the TCP Send‑Q can grow beyond the user‑set SO_SNDBUF value by examining the kernel’s double‑buffer accounting, sk_wmem_queued handling, and the interaction of tcp_sendmsg with GSO, supported by code excerpts and diagrams.
While localhost and 127.0.0.1 are often used interchangeably in web development, this article explains their subtle differences—including hostname versus IP address, resolution processes, performance considerations, IPv6 support, security implications, and practical usage within the TCP/IP model.
This article explains how IPVS (IP Virtual Server) provides layer‑4 load balancing in Linux, compares it with iptables, details its reliance on iptables, outlines the various LVS scheduling algorithms, and provides practical ipvsadm commands for setting up a load‑balancing cluster with real servers.
This comprehensive guide walks developers through the essential concepts of Linux, covering the difference between the kernel and distributions, key command‑line tools, file and permission management, process handling, networking basics, and advanced Vim editing techniques, empowering programmers to become proficient in Linux system operations.
The article walks through every step from typing a URL to final page rendering, detailing URL parsing, DNS lookup, TCP three‑way handshake and termination, HTTP request/response structure, congestion and flow control mechanisms, and the browser’s DOM, CSS, layout and painting processes.
This article explains TCP basics, why raw TCP communication has boundary issues, how custom protocols like HTTP and RPC are built on TCP, and compares their purposes, performance, and usage scenarios in modern software architecture.
This article explains what ports are, why they are essential for web and other services, how default ports work, the role of ports in inter‑process communication, and how they relate to concepts like naming services and inversion of control.
This article explains why a newly plugged‑in computer can instantly obtain an IP address, detailing DHCP’s four‑stage process, the role of UDP broadcasting, packet‑capture commands, unicast optimizations, lease reuse, possible IP conflicts, and the gratuitous ARP messages that follow an ACK.
This article explains the roles, differences, and use‑cases of API gateways, load balancers, and reverse proxies, covering real‑world analogies, types, algorithms, advantages, disadvantages, and practical product examples to help you choose the right component for modern web architectures.
Learn how to set up default gateways, manage multiple network interfaces, add static routes, and use iproute2 and bonding on Linux to achieve dual‑NIC configurations, load balancing and redundancy, with step‑by‑step commands and examples for various network scenarios.
This course provides an in‑depth exploration of core backend concepts—including processes, socket programming with TCP/IP, Nginx‑FASTCGI communication, host‑to‑network byte order conversion, and Redis fundamentals—to equip developers, system administrators, and network engineers with comprehensive backend development skills.
This article explains step‑by‑step what occurs when a user types a URL and presses Enter, covering URL parsing, DNS resolution, TCP three‑way handshake and four‑way termination, HTTP request/response formation, and the browser’s rendering process, providing interview‑ready insights into web networking fundamentals.
This article shares a detailed ByteDance backend interview experience covering three rounds, summarizing essential topics such as Java HashMap internals, Spring circular dependencies, MySQL indexing, OS process/thread concepts, networking protocols, TLS handshake, HTTP/2 features, and common design patterns, providing concise explanations and practical tips.
This article provides concise definitions and explanations of essential networking concepts, including links, OSI model layers, backbone networks, LAN, nodes, routers, VPN, NAT, subnet masks, data encapsulation, TCP/IP, protocols, and security mechanisms, serving as a fundamental reference for beginners.
The IPv4 loopback address 127.0.0.1 (also reachable via the hostname localhost) is reserved for internal communication, so pinging it never leaves the host and works even with the network cable unplugged, while 0.0.0.0 is an unspecified address used only for binding to all interfaces and cannot be pinged.
This article provides concise explanations for 100 fundamental networking questions, covering links, OSI layers, backbone networks, LAN, nodes, routers, point‑to‑point links, anonymous FTP, subnet masks, UTP cable limits, data encapsulation, network topologies, VPN, NAT, routing, fault tolerance, cable standards, IP classes, routing protocols, security measures, NICs, WAN, physical layer, TCP/IP layers, proxy servers, session layer, clustering, antivirus placement, Ethernet, ring topology, CSMA/CD vs CSMA/CA, SMTP, multicast routing, encryption, IP address formatting, authentication, tunnel mode, WAN link technologies, mesh topology, hardware troubleshooting, signal attenuation, DHCP, network permissions, VLANs, IPv6, RSA, and more.
This comprehensive tutorial walks you through DNS fundamentals and advanced topics, covering domain name resolution, zone file structure, SOA and NS records, master‑slave configuration, caching strategies, forwarders, ACLs, views, DNSSEC integration, and powerful management with rndc, all with practical examples.
This article provides a comprehensive overview of the Transmission Control Protocol (TCP), covering its connection‑oriented design, reliability mechanisms, three‑way handshake, four‑step termination, packet structure, flow and congestion control, and practical C++ socket examples for establishing, sending, receiving, and closing connections.
This article explains the difference between decimal and binary data units, how Ethernet frame overhead and protocol headers reduce the theoretical 125 MB/s throughput of a 1 Gbps link, and how increasing the MTU with jumbo frames can improve efficiency.
Ports act as an essential indirection layer that maps network requests to specific processes, enabling protocols like HTTP and HTTPS to function, while default ports simplify user interaction; this article explains common ports, default values, the role of IPC, naming services, and how ports embody inversion of control principles.
This article compiles the most useful Linux networking utilities—such as ping, netstat, lsof, ip, and tcpdump—provides concise explanations, practical command examples, and key tips so readers can quickly recall and apply these tools when troubleshooting network issues.
This guide explains how iptables processes packets, defines rules, tables, and chains, describes common actions like ACCEPT, REJECT, DROP, MASQUERADE, SNAT, DNAT, and MARK, and provides practical command examples for configuring firewall filtering and network address translation on Linux systems.
This article explains what ports are, why default ports like 80 and 443 exist, how ports enable inter‑process communication, act as a naming service and an indirection layer, and why they are essential for both web and non‑web services.
This comprehensive guide explains Docker's networking fundamentals, covering network types such as bridge, host, overlay, and macvlan, their drivers, configurations, security considerations, and practical command‑line examples for creating, managing, and troubleshooting container networks in both single‑host and multi‑host environments.
This article provides an extensive overview of Kubernetes, covering its core architecture, pod IP design, environment setup, networking models, plugins, security measures, backup strategies, monitoring solutions, Helm usage, gray releases, service mesh concepts, and CI/CD pipeline implementation, offering practical insights for developers and operators.
This article explains why remote procedure call (RPC) is essential for modern distributed services, describes the evolution from monolithic to service‑oriented architectures, and details the core components, communication steps, serialization, service discovery, and full call flow of an RPC framework.
Cloudflare has open‑sourced Pingora, a Rust‑based asynchronous multi‑threaded framework for building high‑performance HTTP/1, HTTP/2, gRPC and websocket proxies, highlighting its key features, massive traffic handling, zero‑downtime reloads, observability integrations, and the motivations behind replacing Nginx with Rust.
This article explains how the PHP curl_multi_add_handle() function can add multiple cURL handles to a single multi‑handle session, provides its syntax and parameters, and demonstrates a complete example that shows initialization, adding handles, executing requests concurrently, retrieving responses, and cleaning up.
This article explains how the integration of sriov-network-operator and Kube-OVN automates the complex configuration and persistence of RDMA and SR‑IOV in Kubernetes, enabling high‑availability, multi‑tenant networking for AI distributed training workloads.
This article provides a comprehensive introduction to the TCP/IP protocol stack, explaining its four-layer architecture, the role of each layer from the physical to the application layer, and detailed mechanisms such as framing, addressing, routing, error control, and connection management.
TCP (Transmission Control Protocol) is a connection-oriented, reliable, byte-stream transport layer protocol that ensures ordered, error-free data delivery through mechanisms such as three-way handshake, four-way termination, flow control, and congestion control, making it essential for web browsing, email, and online gaming.
This article reviews common interview questions covering URL request processing, TLS handshake steps, the three‑way TCP handshake and four‑way termination, page‑fault handling, differences between TCP and UDP, HTTP/1.0 vs 1.1, thread‑safety mechanisms in C++, and a hands‑on example of building a thread pool.
Workerman is an open‑source, pure‑PHP high‑performance application container that acts like a PHP‑based Nginx, enabling developers to create TCP/UDP, WebSocket, HTTP services and even custom servers such as Redis or FTP, with multi‑process, epoll and non‑blocking I/O support.
This article explains why keeping the client source IP in an Istio service mesh matters, outlines the reasons for IP loss, and provides step‑by‑step solutions for north‑south and east‑west traffic using Service settings, traffic policies, and Envoy headers.
On Linux, port 53 is typically used by DNS services; this article explains how to interpret systemd-resolve’s UDP and TCP listeners on localhost, analyze netstat output, and provides step‑by‑step commands to disable or reconfigure systemd‑resolved when it occupies the DNS port.
TCP (Transmission Control Protocol) is a core Internet protocol that ensures reliable data transmission through mechanisms such as three‑way handshake, flow and congestion control, segmentation and reassembly, and error detection, while also facing challenges like latency, packet loss, and emerging real‑time application demands.
A single server‑side process can theoretically handle up to 2^48 (≈2.8×10^14) TCP connections, but Linux file‑descriptor limits and memory consumption (about 3.44 KB per connection) restrict real‑world capacity to a few million connections per 8 GB machine, while a whole server’s total is bounded by the same resource constraints despite the much larger theoretical maximum.
The article forecasts rapid eBPF adoption across cloud‑native networking, mobile devices, and observability, highlights emerging eBPF marketplaces, discusses performance gains with NetKit and BIG TCP, predicts IPv6‑first Kubernetes clusters, AI‑assisted network troubleshooting, and the growing convergence of platform engineering and networking in 2024.
This tutorial explains the newly GA Kubernetes Gateway API, its core resources, and how to set up a test environment with K3s and Istio to create GatewayClass, Gateway, and HTTPRoute objects, demonstrating end‑to‑end traffic routing to a sample Nginx service.
The article investigates why applications experience higher latency and lower QPS after moving from virtual machines to Kubernetes containers, analyzes the root causes such as increased soft‑interrupts caused by the networking stack, and proposes optimizations like ipvlan, macvlan, and Cilium to restore performance.
Despite the surge in AI investments, IDC data shows that high‑speed Ethernet continues to outpace InfiniBand in data‑center switch sales, with strong growth in both revenue and port shipments across DC, campus, and edge markets in Q3 2023.
This article examines the global and Chinese switch market size, explains switch definitions and classifications, details hardware components and architectural styles—including Full‑Mesh, Crossbar, and CLOS—covers technical principles, performance metrics, and contrasts with hubs and routers, and explores data‑center and industrial switch deployments and their future challenges.
This article explains the end‑to‑end path that an external HTTP or HTTPS request follows—from the client through DNS resolution, load balancer, ingress controller, service routing, and finally to the target container inside a Kubernetes pod—while also covering optional variations and the underlying network components.
This article examines why IPv6, despite its technical advantages and massive address space, has seen slow adoption, detailing legacy IPv4 workarounds, compatibility and cost hurdles, ISP readiness, and proposes six actionable strategies—including financial incentives, pure‑stack promotion, and government support—to accelerate the transition.
This article presents a comprehensive overview of C++ backend interview topics, covering web server fundamentals, concurrency models, thread pool sizing, epoll integration, I/O multiplexing, HTTP methods, TCP connection handling, debugging techniques, and related networking concepts essential for backend development.
This article explains how Cloudflare replaced NGINX with Pingora, a Rust‑written HTTP proxy that processes over a trillion daily requests, offering superior performance, efficiency, and security through a multithreaded design, custom HTTP library, and programmable request lifecycle.
This article compiles insights from multiple Zhihu contributors who explain how modern operations work spans basic system setup, complex hardware and network management, deep Linux kernel debugging, comprehensive monitoring, rapid incident response, and rigorous security, highlighting why ops expertise is essential and far from low‑level.
This article walks through the entire browser request lifecycle—from entering a URL, resolving the IP via caches and DNS, establishing a secure HTTPS connection, to the server’s response and the browser’s parsing of HTML, CSS, and JavaScript into a rendered page.
This article provides a thorough overview of Java interview topics, covering core language fundamentals, collection frameworks, concurrency mechanisms, Spring Boot transaction handling, database indexing strategies, and network protocol comparisons, all presented in clear English with code examples and diagrams.
This article provides a comprehensive overview of network switches, covering global market trends, definitions, OSI‑based classifications, hardware components, various switching architectures such as CLOS and leaf‑spine, performance metrics, differences from hubs and routers, industrial switch requirements, and the overall industry chain.
Although most users know IPv4 and IPv6, the often‑overlooked IPv5—originally the Internet Stream Protocol—was created for experimental voice and video streaming, never adopted due to 32‑bit address limits, and ultimately paved the way for modern IP technologies.
This article walks through building a minimal Go HTTP server, explains how ListenAndServe internally binds, listens, and accepts connections, details the server’s main loop, request handling, routing logic, and shows how to customize connection and state hooks with concrete code examples.
This comprehensive guide covers essential programming fundamentals—including Python memory management, metaclasses, decorators, multithreading, data structures, algorithmic techniques, database concepts such as ACID, indexing, and transaction isolation, Redis operations, Linux memory handling, networking protocols, Docker/Kubernetes commands, and core testing methodologies—providing clear explanations and practical code examples.
This comprehensive guide answers over one hundred fundamental networking questions, covering topics such as links, OSI model layers, backbone networks, LANs, routers, protocols, IP addressing, subnet masks, security measures, topologies, and many other core concepts essential for understanding computer networks.
This article explains how Linux kernel parameters, memory size, and file descriptor limits determine the maximum number of TCP connections a server or client can handle, provides configuration examples for increasing those limits, and discusses practical considerations such as port ranges and connection overhead.
This comprehensive guide explains TCP fundamentals—including the differences from UDP, the three‑way handshake, four‑way termination, half‑open queues, SYN‑Flood attacks, header fields, Fast Open, timestamps, retransmission timers, flow control, congestion control, Nagle’s algorithm, delayed ACKs, and keep‑alive—providing clear diagrams and practical insights for engineers.
This comprehensive guide answers over one hundred fundamental networking questions, covering links, OSI layers, devices, protocols, IP addressing, security measures, cable types, and network topologies to help readers build a solid understanding of computer networks.
This article provides a detailed walkthrough of a Tencent backend interview covering Java thread models, HashMap internals, garbage collection, operating‑system concepts, process scheduling, IPC mechanisms, I/O multiplexing, virtual memory, networking protocols, Redis data types, MySQL B+‑tree characteristics, and a classic logic puzzle, offering both theory and practical insights.
This article compiles the most common Linux interview questions—covering core components, boot loaders, storage management, networking modes, essential commands, security features, and system administration tricks—providing concise answers and code examples to help developers and sysadmins prepare for technical interviews.
This article examines the technical reasons behind TCP's design as a stream-oriented transport protocol, contrasting it with a packet-oriented approach, and explores the implications for lower and upper layers, packet sizing, application-layer framing, and alternative solutions such as UDP, QUIC, and custom protocols.
TCP and UDP are core transport-layer protocols of the Internet; this article explains their basic concepts, characteristics, reliability mechanisms, flow and congestion control, three-way handshake and four-way termination for TCP, and highlights the strengths and weaknesses of each protocol for various applications.
This article explains how TCP connections are identified by a four‑tuple, clarifies why the theoretical limit of 65,535 ports does not restrict server concurrency, and discusses the practical factors such as memory and file descriptor limits that determine the real maximum number of simultaneous TCP connections on a Linux system.
This personal narrative shares the author’s journey from a new graduate to a chief engineer, offering practical advice on work habits, networking, continuous learning, and career planning for software developers seeking long‑term growth and fulfillment.
Microsoft's latest WSL 2.0.0 preview introduces experimental features such as autoMemoryReclaim and Sparse VHD for improved memory and disk management, adds IPv6 support, DNS tunneling, firewall integration, and various networking enhancements, while also fixing critical bugs and improving GUI application handling.
The article explains how DNS load balancing enables a single domain name to resolve to multiple IP addresses, describes common DNS resolution strategies such as round‑robin, weighted, and response‑time, and outlines the advantages and limitations of using DNS for load distribution.
This article provides a step‑by‑step technical walkthrough of Istio Ambient Mesh traffic flow, detailing how a curl request from a sleep pod on Node‑A reaches an httpbin pod on Node‑B via iptables, policy routing, ztunnel and waypoint components, complete with code snippets and diagrams.
Taobao’s IPv6 journey, from early mobile‑internet growth through five development stages, culminated in a full end‑to‑end architecture that now delivers over 95 % IPv6 traffic, 11 % latency reduction and billion‑user scale, while pioneering innovations such as precise stack detection, multi‑channel competition and future APN6/BIERv6 extensions.
The inaugural CCF China Network Conference held in September 2023 in Wenzhou showcased cutting‑edge AI‑focused networking research, including Alibaba Cloud's Predictable Network and HPN7.0 architecture, AI‑driven network operations, next‑generation data‑center designs, and a collaborative university‑industry network technology challenge.
This article explains WebSocket fundamentals, including its definition, handshake process, data frame structure, binary handling, stream usage, networking details like MTU/MSS, and practical Node.js examples, providing a comprehensive guide for real‑time web communication.
This article explains why the Domain Name System (DNS) is needed, how its hierarchical domain structure works, the design principles of DNS as a high‑concurrency distributed service, its multi‑level caching mechanisms, protocol format, and practical packet‑capture examples.
This article provides an in-depth overview of PHP's cURL library, detailing its core functions, common options such as CURLOPT_URL and CURLOPT_POST, and practical code examples for GET, POST, custom headers, SSL handling, timeouts, file saving, and proxy usage.
This article explains the fundamentals of the Domain Name System (DNS), covering domain and name‑server concepts, the hierarchical resolution process, recursive and iterative queries, performance‑enhancing techniques such as UDP usage, caching, and switching to public DNS servers, and details DNS record types and packet structure.
This article explains how to replace thread‑heavy WebSocket or Socket.IO clients with a Netty‑based Java WebSocket client, covering Maven dependencies, connection setup, event‑loop management, message sending, and a custom channel handler for high‑concurrency scenarios.
This article provides a comprehensive overview of routers, covering their definition, routing and forwarding processes, various hardware and performance classifications, IP addressing, routing protocols, redundancy methods, security features, and management interfaces, all illustrated with clear diagrams.
This guide explains three straightforward command‑line methods—ifconfig, ip addr, and hostname -I—to reliably discover both local and remote IP addresses on a Linux system, helping with network configuration, troubleshooting, and security management.
This article provides a detailed backend interview cheat‑sheet covering Redis data structures and performance issues, MySQL indexing and transaction principles, operating‑system process and thread concepts, TCP/UDP networking differences, and common Java garbage‑collection algorithms, all illustrated with examples and code snippets.
