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XDP Linux: Building an Ultra-Fast Packet Filter at the Driver Layer to Block DDoS

By admin July 2, 2026

XDP (eXpress Data Path) processes and filters packets directly at the NIC driver layer — before they enter the kernel stack — making it 10 to 100 times faster than iptables. This guide covers everything from writing an eBPF program in C, compiling and loading it into the kernel, to managing a real-time IP blocklist with BPF Maps and Python.

Network

Building a Stealth VPN with Xray-core and XTLS-Reality on Linux: Traffic That Looks Like Regular HTTPS

By admin June 27, 2026

A complete A-to-Z guide to installing Xray-core with XTLS-Reality on a Linux server — generating keypairs, configuring VLESS, setting up the client, and monitoring. VPN traffic looks like ordinary HTTPS and cannot be detected or blocked by DPI.

Virtualization

Deploy a VyOS Virtual Router on Proxmox/KVM: Firewall, NAT, and Site-to-Site VPN from A to Z

By admin June 20, 2026

A hands-on guide to deploying a VyOS virtual router on Proxmox or KVM, covering stateful zone-based firewall, NAT masquerade, port forwarding, and IPsec IKEv2 Site-to-Site VPN. Follows a practical workflow from installation to a production-ready lab network.

Network

Mastering hping3: Advanced Techniques for Firewall Bypassing and Deep Network Diagnostics on Linux

By admin June 10, 2026

Don't be fooled by the Ping command. Learn how to use hping3 to craft custom packets, bypass firewalls, and perform deep network diagnostics like a pro SysAdmin.

Security

Stop “Sneaky” Connections on Linux with OpenSnitch: A Powerful Application-Level Firewall

By admin May 14, 2026

Don't let apps leak your data without permission. Learn how to use OpenSnitch to control every network connection on Linux and protect your privacy.

Fedora

Turn Fedora Server into a Pro Router: Optimizing NFTables and Kea DHCP

By admin May 10, 2026

A guide on turning Fedora Server into a professional router. Use NFTables for high-speed firewalling and Kea DHCP for modern local network management.

Security

Moving from iptables to nftables: Why It’s a Mandatory Step for SysAdmins

By admin April 22, 2026

Iptables is outdated and slow. Discover how nftables optimizes firewall performance, supports IPv4/IPv6 simultaneously, and how to safely migrate your Linux system.

Docker

Does Docker ‘Bypass’ UFW? Essential Container Port Security for VPS

By admin April 6, 2026

Why does UFW fail to block Docker ports? Discover 3 practical solutions to resolve Docker firewall bypass issues and protect your VPS from hackers.

Security

Installing and Configuring CrowdSec on Ubuntu: A New Generation Community Server Protection Solution

By admin March 19, 2026

Protecting servers from cyberattacks is a top priority. CrowdSec offers a novel, community-based approach to detect and prevent threats. This article guides you through installing and configuring CrowdSec on Ubuntu.

Centos

Managing Services with firewalld on CentOS/RHEL: A Practical Guide

By admin March 6, 2026

firewalld is the default firewall management tool on CentOS/RHEL, offering flexible zone-based policies that are easier to manage than plain iptables. This article covers practical usage from quick start to rich rules, port forwarding, and tips drawn from real production server management.