A transit card, a hotel key, a payment tap, a pet's microchip — none of them has a battery, yet all of them send data to a reader on demand. They do it by stealing energy from the reader's own field and whispering back by changing how much of it they absorb. This is the physics and the security of the tag.
Networking Deep Dives
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RFID and NFC: How Powerless Tags Talk Back -
BGP Hijacks and RPKI: From Origin Validation to Path Security Internet routing believes whatever it is told, which is why prefixes get hijacked. A practical guide to the cryptographic fix: how RPKI and Route Origin Validation work, the router configs that enforce them, the path-security gap that BGP roles and ASPA are racing to close, and the honest 2026 adoption reality.
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HTTP/3 and QUIC in Production What QUIC actually changed at the wire level, the head-of-line blocking fix, the 0-RTT replay risk and how to harden it, the deployment reality across Cloudflare, Google, and Apple, and the honest performance gains versus HTTP/2 five years after RFC 9000 shipped.
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A Modern CDN, Honestly A multi-line description of two to three lines: how a modern CDN actually works — edge routing, request coalescing, image/video transformation, the cache-key engineering that decides hit rate, and where the big providers differ.
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DDoS Mitigation in 2026 A multi-line description of two to three lines: how modern providers absorb hundreds of Gbps of attack traffic — the attack taxonomy, anycast and scrubbing-center architecture, L7 defenses, and the honest cost of protection.
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eBPF for Networking The Linux kernel grew a programmable packet datapath. Where the hooks actually sit — XDP at the driver edge, tc/clsact in the stack — what each one can and cannot do, how DDoS scrubbing and L4 load balancing get built on them, and the honest operational cost of running eBPF in the datapath.
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WireGuard vs OpenVPN vs Tailscale Three things people call "a VPN" that operate at different layers. The cryptographic protocol differences between WireGuard and OpenVPN, why Tailscale is a control plane rather than a competing protocol, the NAT-traversal story for each, and an honest decision framework for which to actually run.
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DOCSIS and How Cable Internet Works Cable internet is IP smuggled onto coax that was built to carry TV channels, and almost every quirk of how it behaves traces back to that origin. We walk the spectrum layout, why the upstream is the bottleneck, channel bonding and the DOCSIS 3.0/3.1/4.0 progression, the CMTS and modem handshake, bufferbloat under load, and the honest comparison with fiber PON.
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LoRaWAN for Long-Range IoT LoRaWAN sells itself as kilometers of range from a coin cell, and the pitch is true — but only because chirp spread spectrum trades bandwidth and airtime for link budget in ways most builders never think through. This post walks the CSS modulation, the spreading-factor and airtime math, the star-of-stars architecture, duty-cycle regulations, and where LoRaWAN genuinely beats Wi-Fi and cellular versus where the marketing outruns the physics.
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Matter, Thread, and Zigbee Untangled Matter, Thread, and Zigbee are not competitors — they live at different layers of the stack, and most of the confusion in smart-home discussions comes from pretending otherwise. We separate the application layer from the transport, walk the IPv6 mesh that Thread builds, explain border routers and commissioning, and look honestly at what interoperability delivers in 2026 versus what the marketing claims.
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RCS Messaging RCS finally replaced SMS as the default carrier-grade messaging protocol, and the rollout was uglier than the marketing implied. We walk what Universal Profile actually standardizes, the carrier/Jibe split, the Apple interoperability saga, what end-to-end encryption covers in 2026 and what it does not, the SMS fallback that ruins your assumptions, and the honest cross-platform state of the messaging world.
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Starlink: How a LEO Constellation Delivers Low Latency Starlink delivers fiber-grade latency from orbit by trading the old satellite-internet assumption that "satellite" means "high altitude" for the opposite. We walk the physics of a 550 km link, the phased-array dish, satellite handoffs every few minutes, the laser inter-satellite mesh that bypasses ground stations, and the honest trade-offs of capacity, weather, and where this beats fiber and where it does not.
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Wi-Fi 7 and Multi-Link Operation Wi-Fi 7's headline number is 46 Gbps, but the feature that actually changes how your network behaves is Multi-Link Operation. We separate the marketing from the physics: 320 MHz channels, 4096-QAM, the MLO modes nobody explains clearly (STR, eMLSR, eMLMR), why latency and reliability matter more than peak throughput, and what any of it does for a real home network in 2026.
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EtherChannel and Link Aggregation: LACP, PAgP, and When STP Blocks Half Your Bandwidth How EtherChannel bundles multiple physical links into a single logical channel to defeat STP's bandwidth ceiling, with full coverage of LACP, PAgP, static mode, load-balancing algorithms, Layer 2 vs Layer 3 port-channels, and the silent mismatch failures that break aggregation without a clear error message.
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CCNA: First Hop Redundancy Protocols — HSRP, VRRP, and GLBP The default gateway is the single point of failure nobody notices until it dies. First Hop Redundancy Protocols — HSRP, VRRP, and GLBP — put a virtual IP and virtual MAC in front of two or more routers so that when one fails, the other takes over without a host ever changing its gateway. This is a CCNA 200-301 topic 3.5 deep dive: how a virtual gateway works, the HSRP state machine and its v1/v2 differences, priority and preemption, interface tracking, the open-standard VRRP, Cisco's active-active GLBP, and the IOS configuration and verification commands that make it real.
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Network Address Translation (NAT): A CCNA-Focused Guide A comprehensive, CCNA-focused guide to Network Address Translation — why NAT exists, the four address terms (inside local, inside global, outside local, outside global) made memorable, the three flavors (static NAT, dynamic NAT, and PAT/overload) with real Cisco IOS configuration and verification, the inside/outside interface gotcha that breaks every first attempt, how to troubleshoot with show ip nat translations and debug, and NAT's bigger-picture role: the security myths, broken end-to-end connectivity, carrier-grade NAT, NAT64, and how IPv6 changes the story. Built around exam topic 4.6 with commands you can lab.
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Outlets and PoE Drops: Where to Put Power and Network Before the Drywall Goes Up Outlet and network-drop placement is the cheapest decision you'll ever make at rough-in and the most expensive one to fix afterward. This guide covers both halves of the plan: line-voltage outlets — the NEC code floor (the 6/12 rule, kitchen 2/4 spacing, GFCI zones), the rooms where code-minimum isn't enough, and the odd-but-brilliant locations like switched soffit outlets for holiday lights, garage-ceiling receptacles, and in-drawer charging — and PoE drops, including exactly where camera drops belong (eave corners, choke points, 8–10 feet high), why even Wi-Fi cameras like Ring deserve a drop, ceiling access points, doorbells, and the planning mechanics of PoE budgets, conduit, service loops, and surge protection.
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The Complete CCNA 200-301 Study Guide: Every Topic, Linked A single map of the entire CCNA 200-301 (v1.1) exam blueprint — all six domains from Network Fundamentals to Automation and Programmability — with every exam topic linked to an in-depth post that covers it. Use this as the index to the whole CCNA series: subnetting, switching, VLANs and trunking, spanning tree, OSPF, NAT, ACLs, DHCP/DNS/NTP, wireless, first hop redundancy, security, and network programmability, plus an honest note on what is in scope, what changed in v1.1, and how the domains are weighted.
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IP Address Management (IPAM): A CCNA-Focused Guide A comprehensive, CCNA-focused guide to IP Address Management — what IPAM is, the IPv4 address space and RFC 1918 you have to manage, subnetting and VLSM worked the way the exam expects, DHCP (the DORA process, Cisco IOS server and ip helper-address relay config), DNS record types, IPv6 addressing (global unicast, link-local, EUI-64, SLAAC vs DHCPv6), and how real IPAM is done with spreadsheets, phpIPAM, NetBox, and full DDI platforms like Infoblox. Built around the 200-301 IP Connectivity and IP Services domains, with real config and address plans.
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Wiring a Home Remodel for Network: Cable, Drops, Switches, and APs If the walls are open, this is the cheapest they will ever be to wire. A practical guide to networking a home remodel in 2026 — what cable to run (Cat6 vs Cat6A), how many drops per room, where to put the panel and access points, and which switches and PoE gear to buy — written for someone planning the runs, not pulling them blind.
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Anycast Explained: One IP Address, Served From Everywhere A deep technical look at anycast routing — how the same IP prefix is announced from dozens of BGP locations simultaneously, why the internet's most critical infrastructure depends on it, and the real-world trade-offs operators face.
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IPv6 Basics: Why We Need It, How It Differs from IPv4, and What It Unlocks IPv6 quietly crossed 50% of Google's traffic in early 2026. A from-scratch explanation of why the internet ran out of IPv4 addresses, how IPv6 actually differs beyond just being bigger, and the genuinely useful things a 128-bit address space makes possible.
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MTU, MSS, and the Path-MTU Black Hole A deep dive into MTU, MSS, and Path MTU Discovery — the unglamorous packet-sizing concepts behind a whole class of baffling 'connects but then hangs' bugs, and how to diagnose and fix them.
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NAT Traversal: STUN, TURN, ICE, and How Peers Punch Through A deep technical look at how STUN, TURN, and ICE coordinate to let two devices behind NAT establish direct peer-to-peer connections — and what happens when they can't.
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traceroute, ping, and the Network Troubleshooting Toolkit How ping, traceroute, mtr, and a dozen supporting tools actually work under the hood, plus a practical symptom-to-tool methodology for diagnosing network problems from first principles.
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What Happens When You Type a URL and Press Enter A technically precise, end-to-end walkthrough of every major step between pressing Enter and pixels appearing on screen — from URL parsing and DNS to TCP, TLS 1.3, HTTP, CDN routing, and the browser's critical rendering path.
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Routers Inside the Enterprise: What They Do Besides Reach the Internet Most people picture a router as the box between the LAN and the internet. Inside a real company network, routing does far more — connecting subnets, bounding broadcast domains, enforcing security zones, linking sites, and surviving failures. A tour of why internal routing exists.
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Subnetting Explained: Why Subnet Masks Aren't Just 255s and 0s A from-intuition walk through subnetting, and a direct answer to the question every beginner eventually asks: would you ever use a subnet mask octet that isn't 255 or 0? Yes — constantly — and here is exactly when and why.
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Containerlab: Network Labs in Containers Containerlab brings infrastructure-as-code discipline to network emulation — declarative YAML topology files, container-native NOSes, and CI-ready teardown cycles that make GNS3 feel like a different era.
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gRPC From the Ground Up A dense, no-marketing-fluff guide to gRPC: HTTP/2 foundations, the four call types, deadlines, interceptors, the error model, load-balancing gotchas, and when to reach for Connect or REST instead.
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QUIC and HTTP/3 Deep Dive A technical deep dive into why QUIC replaces TCP under HTTP/3: head-of-line blocking, the integrated TLS 1.3 handshake, independent streams, connection migration, and the honest operational reality of deploying it with nginx, Caddy, and Cloudflare.
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CCNA: Network Automation and Programmability REST APIs, JSON data formats, Python network automation with netmiko and NAPALM, Ansible for network devices, and Cisco DNA Center/Catalyst Center — CCNA-level programmability concepts with practical examples.
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CCNA: Network Security Fundamentals Port security with sticky MAC and violation modes, DHCP snooping, Dynamic ARP Inspection, IP Source Guard, 802.1X port-based authentication, and management plane hardening on Cisco IOS — CCNA-level coverage with practical configuration examples.
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CCNA: Wireless Networking Fundamentals 802.11 wireless standards from a/b/g through Wi-Fi 6E and 7, 2.4/5/6 GHz channel planning, BSS/IBSS/ESS topologies, WPA2 vs WPA3 security, autonomous vs lightweight AP architectures, and basic Cisco WLC configuration — CCNA-level coverage.
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Cisco IOS Command Walkthroughs A practical annotated reference of essential Cisco IOS commands organized by task — initial setup, interfaces, routing, switching, NAT, ACLs, DHCP, and diagnostics — with real output explained field by field.
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CCNA: ACLs — Standard, Extended, and Named A complete guide to Cisco IOS Access Control Lists for CCNA: standard vs extended, numbered vs named, wildcard masks, implicit deny, placement rules, editing ACLs, and every show and debug command you need for verification and troubleshooting.
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CCNA: DHCP, DNS, and NTP on IOS Configuring DHCP server, DHCP relay, DNS resolution, and NTP time synchronisation on Cisco IOS — complete configuration, verification commands, and troubleshooting for all three protocols.
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CCNA: EIGRP Fundamentals EIGRP from first principles: DUAL algorithm, successor and feasible successor selection, the feasibility condition, composite metric calculation, unequal-cost load balancing, neighbor tables, topology tables, and complete Cisco IOS configuration and verification.
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CCNA: Ethernet and Switching Fundamentals A comprehensive deep-dive into Ethernet and Layer 2 switching — MAC address learning, the CAM table, flooding vs forwarding, broadcast domains, duplex and autonegotiation, Cisco IOS switching commands, and how a frame actually traverses a switched network.
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CCNA: IPv4 Addressing and Subnetting A complete guide to IPv4 addressing and subnetting for CCNA — binary conversion, CIDR, subnet masks, the magic number method that works under exam pressure, VLSM design, and route summarization with fully worked examples.
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CCNA: IPv4 Routing Fundamentals How routers make forwarding decisions, the routing table in depth, administrative distance, static routes with next-hop vs exit-interface, default routes, recursive lookups, and connected/local routes — with full Cisco IOS CLI examples.
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CCNA: NAT and PAT — Network Address Translation in Depth Static NAT, dynamic NAT, and PAT explained from first principles — inside/outside local/global address terminology, full Cisco IOS configuration, NAT translation table interpretation, debug ip nat output, and troubleshooting every common failure mode.
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CCNA: OSPF Single-Area Configuration OSPF from first principles through production configuration: link-state database, DR/BDR election, the seven neighbor states, Hello/Dead timers, LSA types, passive interfaces, cost tuning, and complete Cisco IOS CLI examples.
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CCNA: Spanning Tree Protocol — STP, RSTP, and Why Layer 2 Loops Are Catastrophic A complete guide to Spanning Tree Protocol for CCNA candidates and working engineers: why STP exists, the bridge election process, port states, RSTP improvements, PortFast, BPDU Guard, and full Cisco IOS configuration with annotated CLI output.
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CCNA: The OSI and TCP/IP Models in Practice Layer by layer from physical to application — where each protocol lives, how encapsulation actually works, and how to use the model to troubleshoot real connectivity problems rather than just pass an exam.
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CCNA: VLANs and Trunking — Complete Guide A comprehensive guide to VLANs and trunking for CCNA candidates and engineers solidifying foundational networking knowledge — 802.1Q frame structure, DTP, native VLANs, VLAN hopping attacks, VTP, inter-VLAN routing with router-on-a-stick and SVIs, voice VLANs, and full IOS CLI examples.
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CCNA: WAN Technologies and PPP WAN link types, PPP encapsulation with PAP and CHAP authentication, PPPoE client configuration on Cisco IOS, and SD-WAN as a modern WAN replacement — CCNA-level coverage with practical IOS examples.
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HAProxy Deep Dive: Load Balancing, ACLs, and SSL Termination at Scale The HAProxy configuration DSL from first principles: frontends, backends, ACL-based routing, all load balancing algorithms, stick tables for rate limiting, SSL termination with automatic certificate renewal, the runtime API, and Prometheus observability — all without a sidecar.
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Tailscale and the Zero-Trust Home Network How Tailscale works under the hood — WireGuard, NAT traversal, DERP relays, the coordination server — and a practical guide to subnet routing, exit nodes, Funnel, ACLs, and self-hosting with Headscale.
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DNSSEC Setup and Operation: KSK/ZSK Rotation, DS Publication, and Validation Debugging A practical guide to deploying DNSSEC — how zone signing prevents spoofing and cache poisoning, KSK/ZSK key rollover, getting DS records published at the parent, and debugging validation failures when resolvers go bogus.
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FRRouting in Production: The Linux Router That Replaces Cisco for Many Use Cases FRRouting turns commodity Linux into a serious router — the stack behind Cumulus, SONiC, and Cilium's BGP mode. How to run BGP and OSPF in production, and where FRR is a genuine alternative to Cisco and Juniper.
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Kea DHCP: The Successor to ISC DHCP A migration and getting-started guide for Kea, ISC's ground-up replacement for the end-of-life dhcpd — its JSON config model, hooks, REST API, and built-in high availability, with mappings from old dhcpd.conf patterns.
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OSPF for DevOps Engineers: Link-State Routing Without the CCNA OSPF link-state routing explained for DevOps engineers, not CCNA candidates — enough theory to run multiple routers with FRR in a homelab or datacenter, understand areas and LSAs, and debug why a route isn't where you expect.
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Wireshark and tshark for Engineers: Capture Filters, Display Filters, and Scripting Batch Analysis Wireshark and tshark past the basics — capture versus display filters, following streams, decrypting TLS, and scripting tshark for batch analysis — the parts that turn 'I took a capture' into 'I found the problem in thirty seconds'.
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RDMA and InfiniBand From the Ground Up: Why It's Fast and How to Diagnose It Why RDMA and InfiniBand deliver 400 Gbps at single-microsecond latency with the CPU idle — how kernel-bypass and the verbs model work, how RoCE differs, and how to diagnose a fabric that isn't hitting its datasheet.
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Proxmox SDN: Software Defined Networking A deep dive into Proxmox VE's Software Defined Networking: zones, VNets, VXLANs, EVPN with BGP peering, multi-tenant overlay networks, and building isolated network segments across a Proxmox cluster.
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Traefik as a Kubernetes Ingress Controller: The Complete Guide A technically deep guide to running Traefik as a Kubernetes ingress controller — covering Helm installation, IngressRoute CRDs, Middleware resources, TLS with cert-manager, Gateway API, RBAC, high availability, observability, and production-grade patterns including canary deployments, TCP/UDP routing, and ForwardAuth with Authentik.
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Tailscale: The WireGuard Mesh VPN That Actually Works Everywhere A deep technical guide to Tailscale: how the mesh VPN works under the hood, complete setup for every platform, subnet routing and exit nodes for homelab access, ACL policy files, MagicDNS, Tailscale Funnel and Serve, self-hosting the control plane with Headscale, and an honest comparison with WireGuard, ZeroTier, and Netbird.
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Home Network Monitoring with ntopng and LibreNMS Build a complete home network monitoring stack using ntopng for deep traffic analysis and LibreNMS for SNMP-based device health — with Grafana dashboards tying everything together.
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DNS over HTTPS and DNS over TLS: Encrypting the Internet's Phone Book A deep dive into DNS over HTTPS (DoH) and DNS over TLS (DoT): why plain DNS is a privacy and security problem, how encrypted DNS protocols work, deploying your own resolver, and configuring clients.
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Gateway API: The Future of Kubernetes Ingress The Kubernetes Gateway API replaces Ingress with a role-oriented, expressive API for HTTP routing, traffic splitting, header manipulation, and TCP/gRPC routing. Here's everything you need to migrate.
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HAProxy Deep Dive: Load Balancing, Health Checks, ACLs, and Production Tuning A comprehensive guide to HAProxy — covering load balancing algorithms, health checks, ACLs and routing logic, SSL/TLS termination, rate limiting, observability, and tuning for high-traffic production workloads.
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BGP for Engineers: How the Internet Routes Itself A practical guide to Border Gateway Protocol — how eBGP and iBGP work, route selection, path attributes, and running BGP in the datacenter with FRRouting.
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DPDK and High-Performance Networking: Kernel Bypass for Line-Rate Packet Processing A deep dive into DPDK — how kernel bypass works, poll-mode drivers, memory management with hugepages, building packet processing applications, and when DPDK is (and isn't) the right tool.
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IPv6 Practical Guide: Addressing, Dual-Stack, and Running IPv6 in Your Homelab A hands-on guide to IPv6 — addressing schemes, SLAAC vs DHCPv6, dual-stack configuration, prefix delegation, firewalling, and running IPv6 end-to-end in a homelab or production network.
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Network Observability with Cilium and Hubble: Complete Visibility Into Your Kubernetes Network A comprehensive guide to Cilium and Hubble — installing the eBPF-based CNI, capturing flow logs, debugging network policies, building Grafana dashboards, and achieving complete network visibility in Kubernetes.
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Network Segmentation with VLANs: Isolating Traffic on Your Homelab and Beyond A practical guide to network segmentation using VLANs — how they work, configuring managed switches, setting up VLANs on pfSense/OPNsense, isolating IoT devices, creating a DMZ, inter-VLAN routing, and Linux trunk configuration.
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pfSense and OPNsense: The Complete Home Lab Firewall Guide A comprehensive guide to pfSense and OPNsense — comparing the two platforms, choosing hardware, installing and configuring from scratch, setting up DHCP, DNS-over-TLS, firewall rules, NAT, VLANs, WireGuard, high availability with CARP, packages like pfBlockerNG and Suricata, and hardening your router/firewall for the home lab or small business.
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WireGuard VPN: Fast, Modern, and Actually Understandable A complete WireGuard guide — how it works, server and peer setup, split tunneling, road warrior config for laptops and phones, site-to-site networking, key management, and troubleshooting.
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Traefik: The Complete Guide to the Cloud-Native Reverse Proxy A comprehensive deep-dive into Traefik — the modern cloud-native reverse proxy and load balancer. Covers core architecture, Docker auto-discovery with labels, automatic HTTPS via Let's Encrypt, the full middleware ecosystem, routing rules, ForwardAuth and SSO, observability, HTTP/3, and the tips and tricks that make it the go-to proxy for home labs and production Kubernetes clusters alike.