Fwknop on Michele Bolognahttps://www.michelebologna.net/tags/fwknop/Recent content in Fwknop on Michele BolognaHugoenThu, 11 Jun 2026 00:00:00 +0000Why I close SSH port 22 entirely (and what I use instead)https://www.michelebologna.net/2026/ssh-port-22-fwknop-single-packet-authorization/Thu, 11 Jun 2026 00:00:00 +0000https://www.michelebologna.net/2026/ssh-port-22-fwknop-single-packet-authorization/<p>Most SSH hardening guides stop at key-only auth and <a href="https://www.fail2ban.org/" class="external-link" target="_blank" rel="noopener">fail2ban</a>. That helps, but if your machine has a public IP, port 22 is still open to the internet. Every automated scanner can probe it and get a response: the SSH version string, the banner, proof that something is listening.</p>