Linux Networking and Security: A Practical Guide to Firewalls, VPNs, and Secure Server Administration

Master Linux networking from the command line up—secure servers, deploy enterprise VPNs, and build bulletproof firewalls that actually survive real attacks. Key Features • Hands-On Firewall Mastery — Configure iptables and nftables from first principles, with production-tested rule sets you can deploy today • Complete VPN Implementation — Build secure remote access with both OpenVPN and WireGuard, including certificate management and key distribution • Server Hardening Playbook — Lock down SSH, web services, and network daemons using Fail2ban, SELinux, and AppArmor • Infrastructure Resilience — Deploy HAProxy load balancers and Keepalived failover clusters that keep services online Book Description Linux powers the internet backbone, yet most administrators learn networking by fixing outages at 3 AM. This book closes that gap with systematic, battle-tested techniques for building secure, scalable infrastructure from the ground up. Starting with core networking concepts and essential commands, you'll progress through Linux's entire security stack. Master iptables for legacy environments, then migrate to modern nftables with confidence. Deploy remote access solutions using both OpenVPN for complex scenarios and WireGuard for performance-critical setups—complete with firewall integration and troubleshooting workflows. The security focus extends beyond perimeter defense. You'll harden SSH against brute-force attacks, protect web services, and implement mandatory access controls with SELinux and AppArmor. For high-availability demands, configure HAProxy load balancing and Keepalived failover to eliminate single points of failure. Advanced chapters cover SSH tunneling strategies and persistent port forwarding for secure remote administration. Every chapter includes configuration templates, command references, and diagnostic techniques derived from real production environments. Whether you're securing a single server or designing multi-site infrastructure, this book provides the practical depth that documentation glosses over. What You Will Learn • Configure network interfaces, routing tables, and diagnostic tools using native Linux utilities • Write, test, and maintain iptables rulesets with default policies and persistence across reboots • Deploy nftables for next-generation firewall management with cleaner syntax and atomic rule updates • Architect VPN solutions: select protocols, manage PKI for OpenVPN, and optimize WireGuard for mobile clients • Harden SSH authentication, eliminate password-based entry, and implement fail2ban for automated threat response • Secure web servers and network services against common vulnerability classes • Deploy HAProxy for Layer 4/7 load balancing with health checks and backend failover • Configure Keepalived for automatic IP failover and service continuity • Establish SSH tunnels for encrypted remote access and port forwarding scenarios • Troubleshoot connectivity, firewall blocks, and VPN handshakes using systematic diagnostic methods Who This Book Is For Systems administrators transitioning into network security roles, DevOps engineers managing Linux infrastructure, and IT professionals responsible for server hardening and remote access architecture. Requires basic Linux command-line familiarity; no prior networking certification needed.