Linux Firewall Basics: Locking Down a Server Without Locking Yourself Out
A practical introduction to host firewalls on Linux: default-deny policy, ufw and nftables concepts, safe rule changes, and avoiding SSH lockouts.
Linux Servers & Hosting
Server Security & Maintenance
Server Security & Maintenance guides, comparisons and explainers from CRMServerBase.
Linux Patch Management Without Surprise Outages
Build a dependable Linux patching routine: staging, testing, scheduling reboots and rolling back, so security updates do not cause outages.
SSH Hardening Checklist for Linux Servers
A practical checklist for hardening SSH on Linux servers: key-based login, disabling risky options, limiting exposure and verifying changes safely.
TLS Certificate Renewal: Automating It and Catching Failures Before They Expire
Stop certificate expiry outages: how automated renewal works, why it silently breaks, and the monitoring and testing that catches problems before users do.