- Debian 13: nf_conntrack table full — why connections fail and how to tune safely
- Ubuntu 24.04 “Permission denied” executing scripts: noexec mounts and how to fix (case #58)
- Ubuntu 24.04: IPv6 firewall forgotten — close the real hole (not just IPv4) (case #72)
- Ubuntu 24.04: IPv6 firewall forgotten — close the real hole (not just IPv4) (case #12)
- Debian 13: SSH port changed — fix firewall + sshd order without locking yourself out (case #27)
- Ubuntu 24.04: UFW locked you out — recover SSH access safely from console
- Ubuntu 24.04: Fail2ban isn’t banning anything — the quick verification workflow
- Ubuntu 24.04: SSH hardening that won’t lock you out — a pragmatic checklist
- Ubuntu 24.04: SSH Sessions Drop Randomly — Keepalive Settings That Actually Help
- Debian/Ubuntu Web Root Permissions: Stop 403s Without 777 (Case #69)
- Debian 13: SSH port changed — fix firewall + sshd order without locking yourself out (case #87)
- Debian 13: iptables vs nftables conflict — stop the silent firewall war
- Debian 13: SSH keys rotated — revoke access cleanly and avoid key sprawl (case #73)
- Heartbleed: the bug that showed the internet runs on duct tape