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Found a mistake, an outdated command or a missing topic? Email us. Here is what to include so we can fix it quickly — and where to go for help with your own server.

Updated 2 min read

Email hello@fail2ban.dev for corrections, suggestions and feedback about this site.

fail2ban.dev is an independent documentation site. We are not the fail2ban project, so we can't fix bugs in fail2ban itself or publish its releases — see below for where those go.

Reporting a correction#

Corrections are the most useful thing you can send. A good report includes:

  • The page URL, and the section or code block concerned.
  • What is wrong, quoted from the page.
  • What is right, and how you know: the fail2ban version (fail2ban-client version), your distribution and release, the relevant line from the fail2ban source or man page, or the command output you got.
  • Whether it's version-specific, for example "correct for 1.0.2 on Ubuntu 24.04, but changed in 1.1.0".

Please remove passwords, API tokens and other secrets from any configuration or logs you include, and replace real public IP addresses with documentation addresses such as 203.0.113.42 if you prefer.

We review every correction. When a fix is published, the page's "updated" date changes. Our editorial process is described on the about page.

Suggestions#

Tell us about topics you searched for and couldn't find, services you'd like a guide for, filters that need better explanations, or ideas for the browser tools. Real search phrases and error messages are especially helpful.

Help with your own server#

We can't provide individual support for your servers or debug your configuration by email. These resources will usually get you an answer faster:

  • Troubleshooting guides: the troubleshooting section covers the common problems — jails not banning, "no log file found", Docker, reverse proxies and configuration errors.
  • FAQ for quick answers.
  • Your distribution's community: forums, mailing lists or Q&A sites for Ubuntu, Debian, Fedora, Arch and others.

Bugs in fail2ban itself#

If fail2ban crashes, a stock filter misses a log format, or behaviour contradicts its documentation, report it to the project on GitHub: github.com/fail2ban/fail2ban/issues. Search existing issues first, and include your fail2ban version, distribution, the jail and filter involved, and sample log lines. Security vulnerabilities should follow the project's security policy on GitHub rather than a public issue.

Privacy#

Emails are used only to reply and to improve the site. See the privacy policy for details.

All problemsfail2ban troubleshooting: match your symptom or exact error message to the fix, and use a 6-step debugging routine that finds most fail2ban problems in minutes.About fail2ban.devWho runs fail2ban.dev, what it covers, and how pages are checked against the fail2ban source code, upstream config files and real command output.FAQAnswers to common fail2ban questions: is it a firewall, is it needed with SSH keys, does it stop DDoS, IPv6, iptables vs nftables, Cloudflare, Windows, GUI and more.Privacy policyfail2ban.dev privacy policy: no accounts, browser-only tools that never upload your logs, Cloudflare and Google Analytics, cookies and your GDPR/CCPA rights.

Spotted something wrong or out of date? Tell us — every page is checked against the current fail2ban release.