My problem with Arch Linux
How I fixed a broken GRUB on a fully encrypted Arch Linux disk after a bad config change.
Blog
10 posts and counting.
AWS: Simple and Secure Architecture
How to deploy a secure VPC on AWS with EC2, Bastion Host, NAT Gateway, and ELB from scratch.
Magic Commands: Grep!
A practical guide to grep with real examples: filtering logs, searching patterns, regex and bash scripting.
Magic Commands: Find!
A practical guide to find with real examples: searching by name, type, user, permissions, and executing actions.
Scanning with Nmap: Gathering Info
A practical Nmap scanning strategy: service fingerprinting, OS detection, timing control, and advanced flags.
Nmap Port Scanning Techniques
A guide to the main Nmap scanning techniques: TCP Connect, SYN, Idle, ACK, X-Mas, and Null scan.
Installing Packages on CentOS Offline
How to install RPM packages with all their dependencies on an internet-restricted CentOS server using repotrack and createrepo.
What is SSH?
An introduction to SSH: what it is, how encryption works, and why it replaced Telnet as the standard for remote server management.
SSH: Public Key Authentication
How SSH public key authentication works, how to generate ECDSA and RSA key pairs, and how to deploy them to your server securely.
Configuring the SSH Server
A practical guide to hardening sshd_config: disable root login, enforce key-only auth, restrict users, and tune the most important SSH server settings.