F
Hosting & infrastructure
Fail2Ban
Open-source intrusion prevention that bans IPs after repeated failed logins.
Open-source intrusion prevention that bans IPs after repeated failed logins.
Fail2Ban is open-source intrusion-prevention software for Linux servers. It watches your log files for signs of abuse, above all repeated failed login attempts, and responds by updating the server firewall to ban the offending IP address for a set period.
It has been a standard hardening tool for sysadmins for two decades: lightweight, configurable per service (SSH, mail, web), and entirely free. You install it once, and it quietly turns brute-force attacks into short-lived bans.
Fail2Ban is the first thing Ian Kilpatrick installs on any new server, and in Session 008 it was step one of his security checklist for agent deploys: put the OpenClaw on a server, put up the firewalls, install Fail2Ban. It bans an IP for 24 hours after about 5 failed login attempts, which dispels most of the automated attack traffic a public server attracts, and it is something he only learned about once he started running agents on servers of his own.
The reason it matters for this audience: the moment your agent lives on a public server, login bots start hammering it, whether or not anything valuable is behind the door. Fail2Ban plus a firewall plus keeping API keys out of the codebase is the whole baseline, and all three are free. Pair it with Alec's blast-radius question (what happens if this data leaks?) to decide whether you need anything heavier.
Anyone who followed the AI4NTP path of putting an agent on its own cloud server. If you have a DigitalOcean droplet running OpenClaw, Fail2Ban is the ten-minute install that stands between you and every SSH brute-force bot on the internet. Your agent can install and configure it for you; just ask it to.
Yes, Fail2Ban has a free tier. Free and open source (GPL).
Free and open source (GPL).
Ian Kilpatrick used it in Session 008 for first install on any new OpenClaw server: bans IPs for 24 hours after about 5 failed logins.
Anyone who followed the AI4NTP path of putting an agent on its own cloud server. If you have a DigitalOcean droplet running OpenClaw, Fail2Ban is the ten-minute install that stands between you and every SSH brute-force bot on the internet. Your agent can install and configure it for you; just ask it to.
| Category | Hosting & infrastructure |
|---|---|
| Pricing | Free and open source (GPL). |
| Free tier | Yes |
| Used live in | Session 008 |
| Operator(s) | Ian Kilpatrick |
| Website | github.com/fail2ban/fail2ban |
On AI4NTP, every tool is shown live by a real operator. These are the people who demoed Fail2Ban on stage.
A designer, developer, and serial entrepreneur writing code since age 10. He has worked with Disney, the Golden Globes, and the AMAs, and now runs a fleet of AI agents doing real work every day.
Explore other tools we've demoed live at AI4NTP:
See tools like Fail2Ban set up live, step by step, on AI4NTP, or get hands-on help putting it to work.