Networking

Generate a fresh rndc.key and wire it into rndc.conf so your BIND name server accepts authenticated remote control commands. Covers the rndc-confgen command and the full rndc.conf structure.

Exim offers two DKIM-related toggles that work together to validate and enforce sender signatures. Setting both to On ensures your mail server actually checks incoming DKIM records and rejects messages that fail validation.

A DNS amplification attack floods a victim with forged responses by exploiting open resolvers. This post walks through iptables rules and BIND hardening steps to block the attack vector.

A practical walkthrough of how DNS resolution works, from the hierarchical name space down to the iterative query process. Includes common zone file syntax mistakes and how to avoid them.

A quick Apache mod_rewrite snippet that forces all HTTP traffic to HTTPS, plus context on where to place it and what to watch for.

A quick way to throttle inbound HTTP traffic to your Apache server using iptables, protecting it from traffic spikes and simple DoS attempts.