https://fail2ban.dev/Independent documentation and free tools for fail2ban: install guides, fail2ban-client commands, jail.local configuration, filters, an online fail2ban-regex tester and fixes for common errors.enhttps://fail2ban.dev/troubleshooting/high-cpu/https://fail2ban.dev/troubleshooting/high-cpu/fail2ban at 100% CPU, high memory or "too many open files"? Fix the polling backend, huge logs, slow regexes, journal file handles and an oversized database.Mon, 26 Oct 2026 08:00:00 +0000https://fail2ban.dev/troubleshooting/config-errors/https://fail2ban.dev/troubleshooting/config-errors/Fix fail2ban errors: No failure-id group in, No section: 'Definition', jail does not exist, nft or iptables not found, and the allowipv6 not defined warning.Mon, 26 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/proxmox/https://fail2ban.dev/guides/proxmox/Install fail2ban on Proxmox VE 8 and 9: create the proxmox filter Debian lacks, add a journal jail for the 8006 web UI and SSH, plus Backup Server, PMG and LXC.Mon, 26 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/openwrt/https://fail2ban.dev/guides/openwrt/Run fail2ban on an OpenWrt router: install it, log to a file, use nftables, add dropbear and LuCI jails, and see when banIP's log monitor fits better.Mon, 26 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/minecraft/https://fail2ban.dev/guides/minecraft/Ban bots that keep trying to join a whitelisted Minecraft server: a tested fail2ban filter for latest.log (vanilla and Paper), the jail, Docker and limits.Mon, 26 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/docker/https://fail2ban.dev/guides/docker/fail2ban and Docker: run it in a container with crazymax or linuxserver compose files, or ban in DOCKER-USER so published ports are blocked. Logs and fixes.Mon, 26 Oct 2026 08:00:00 +0000https://fail2ban.dev/faq/https://fail2ban.dev/faq/Answers 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.Mon, 26 Oct 2026 08:00:00 +0000https://fail2ban.dev/config/email-alerts/https://fail2ban.dev/config/email-alerts/Set up fail2ban email alerts with action_mw or action_mwl, send via any SMTP server with msmtp, stop start/stop mails, and fix alerts that are not sending.Mon, 26 Oct 2026 08:00:00 +0000https://fail2ban.dev/versions/https://fail2ban.dev/versions/The latest fail2ban version is 1.1.1. Check your installed version, see what changed in 1.1.1, which version each distro ships, and how to upgrade safely.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/unban-ip/https://fail2ban.dev/unban-ip/Unban an IP in fail2ban with fail2ban-client: from one jail, from all jails, unban everything, IPv6 and Docker, and stop the same IP getting banned again.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/troubleshooting/reverse-proxy-ip/https://fail2ban.dev/troubleshooting/reverse-proxy-ip/fail2ban behind a reverse proxy or load balancer bans 127.0.0.1 or the proxy IP? Log the real client IP with real_ip, mod_remoteip or trusted proxies.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/troubleshooting/not-banning/https://fail2ban.dev/troubleshooting/not-banning/fail2ban not working? Find out if the jail fails to ban or bans without blocking, then fix the log source, filter, ignoreip, thresholds, port or firewall.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/troubleshooting/no-log-file/https://fail2ban.dev/troubleshooting/no-log-file/Fix the fail2ban error "Have not found any log file for sshd jail" on Debian 12 and journal-only systems: switch to backend = systemd or correct the logpath.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/troubleshooting/exit-code-255/https://fail2ban.dev/troubleshooting/exit-code-255/fail2ban.service exited with status=255/EXCEPTION? Find the real error with journalctl and fail2ban-client -t, then fix missing logs, config typos or Python 3.12.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/troubleshooting/could-not-find-server/https://fail2ban.dev/troubleshooting/could-not-find-server/Fix fail2ban-client errors "Failed to access socket path … Is fail2ban running?" and "Could not find server": start the service, use sudo, clear stale sockets.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/troubleshooting/https://fail2ban.dev/troubleshooting/fail2ban 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.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/tools/regex-tester/https://fail2ban.dev/tools/regex-tester/Free online fail2ban regex tester. Paste log lines, pick any built-in filter or write a failregex with <HOST>, and see matches, missed lines and IPs to ban.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/tools/log-analyzer/https://fail2ban.dev/tools/log-analyzer/Paste auth.log, secure, journalctl or nginx/Apache logs and see attacking IPs, failures per hour, usernames tried and which IPs fail2ban would ban. Runs locally.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/tools/jail-generator/https://fail2ban.dev/tools/jail-generator/Free fail2ban jail.local generator. Pick your distro, firewall and services, set bantime, findtime, maxretry and ignoreip, and copy a clean, commented config.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/tools/filter-generator/https://fail2ban.dev/tools/filter-generator/Generate a fail2ban filter from one log line: click the IP, get a working failregex with <HOST>, a filter.d file, a jail and the fail2ban-regex test command.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/tools/command-builder/https://fail2ban.dev/tools/command-builder/Build the exact fail2ban-client command for your jail and IP: unban, ban, list banned IPs, whitelist, read or change settings, reload — with sudo or Docker.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/tools/bantime-calculator/https://fail2ban.dev/tools/bantime-calculator/Free fail2ban bantime calculator: convert values like 1d12h, 1w or 1mo to seconds, and see how long each repeat ban lasts with your bantime.increment settings.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/tools/https://fail2ban.dev/tools/Free fail2ban tools in your browser: an online fail2ban-regex tester, filter and jail.local generators, bantime calculator, log analyzer and command builder.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/status/https://fail2ban.dev/status/Check fail2ban status with systemctl and fail2ban-client status sshd, and what Currently failed, Total failed, Currently banned and Total banned really mean.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/security/https://fail2ban.dev/security/fail2ban vulnerabilities and CVEs: CVE-2026-109786, the GHSA-33wh-ccjc-p397 ReDoS, CVE-2021-32749, the action.d privilege escalation and how to check your server.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/reload/https://fail2ban.dev/reload/fail2ban restart vs reload explained: reload config or one jail, restart a jail, clear bans with --unban, and test your configuration first with fail2ban-client -t.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/logs/https://fail2ban.dev/logs/Where fail2ban logs (/var/log/fail2ban.log or the journal), how to read Found, Ban and Unban lines, change the log level, rotate logs and grep for top banned IPs.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/install/ubuntu/https://fail2ban.dev/install/ubuntu/Install fail2ban on Ubuntu 24.04, 22.04 or 26.04: versions per release, what defaults-debian.conf changes, the sshd jail, UFW integration and how to verify bans.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/install/rhel/https://fail2ban.dev/install/rhel/Install fail2ban on Rocky Linux, AlmaLinux, RHEL 9/10, CentOS Stream and Fedora with dnf: EPEL, the firewalld ban action, systemd journal and SELinux.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/install/debian/https://fail2ban.dev/install/debian/Install fail2ban on Debian 12, Debian 13 or Raspberry Pi OS: fix the missing auth.log with backend = systemd, ban with nftables, protect SSH and verify it.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/install/arch/https://fail2ban.dev/install/arch/Install fail2ban on Arch Linux or Manjaro with pacman: 1.1.1 from extra, systemd journal backend, nftables bans, the sshd jail and optional service hardening.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/install/https://fail2ban.dev/install/How to install fail2ban on Ubuntu, Debian, Rocky, Fedora, Arch, Docker and from source (1.1.1), then enable the sshd jail, start the service and verify it.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/how-it-works/https://fail2ban.dev/how-it-works/What fail2ban is and how it works: server and client, jails, filters with failregex, ban actions, backends, findtime/maxretry/bantime, the ban database and recidive.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/wordpress/https://fail2ban.dev/guides/wordpress/Protect WordPress with fail2ban: the WP fail2ban plugin and its wordpress-hard/soft filters, or a plugin-free access-log filter for wp-login.php and xmlrpc.php.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/wireguard/https://fail2ban.dev/guides/wireguard/Does fail2ban work with WireGuard? Why WireGuard logs no failed handshakes, the kernel debug-log workaround and its risks, and what to protect with fail2ban instead.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/vaultwarden/https://fail2ban.dev/guides/vaultwarden/Protect Vaultwarden with fail2ban: enable LOG_FILE, use the vaultwarden filter from fail2ban 1.1.1, ban in DOCKER-USER, add a stricter admin page jail, and test.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/ufw/https://fail2ban.dev/guides/ufw/Use fail2ban with UFW: set banaction = ufw or keep nftables, why ufw limit alone isn't enough, Ubuntu 24.04 setup and how to check bans in ufw status.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/traefik/https://fail2ban.dev/guides/traefik/Use fail2ban with Traefik: enable the access log, the traefik-auth filter and its modes, a 404 jail, Docker Compose, DOCKER-USER bans, real IPs and CrowdSec.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/ssh/https://fail2ban.dev/guides/ssh/Protect SSH with fail2ban: a working sshd jail, systemd backend, custom SSH port, aggressive mode for key-only servers, sshd-session on OpenSSH 9.8+ and tests.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/postfix-dovecot/https://fail2ban.dev/guides/postfix-dovecot/Protect a mail server with fail2ban: postfix, postfix-sasl and dovecot jails, filter modes, systemd journal setup, Dovecot 2.4 logs and mailcow/iRedMail notes.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/openvpn/https://fail2ban.dev/guides/openvpn/Set up fail2ban for OpenVPN: the openvpn filter for TLS handshake and auth failures, a UDP 1194 jail, journal vs log-append logging, and the ovpn-server name trap.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/nginx/https://fail2ban.dev/guides/nginx/Set up fail2ban for nginx: nginx-http-auth, nginx-botsearch, nginx-limit-req with limit_req_zone, bad requests, forbidden, a 404 filter and real IPs behind a proxy.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/nginx-proxy-manager/https://fail2ban.dev/guides/nginx-proxy-manager/Add fail2ban to Nginx Proxy Manager in Docker: NPM log paths and format, a tested 401/403/404 filter, the DOCKER-USER jail, Cloudflare, Unraid and Proxmox.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/nftables/https://fail2ban.dev/guides/nftables/fail2ban's nftables action explained: the inet f2b-table, addr-set sets, multiport vs allports, listing bans with nft, IPv6, Debian 12/13 and nft not found.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/nextcloud/https://fail2ban.dev/guides/nextcloud/Protect Nextcloud with fail2ban: a tested Login failed filter for nextcloud.log, the jail, Docker, AIO and snap log paths, and trusted_proxies.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/mysql/https://fail2ban.dev/guides/mysql/Stop database brute force with fail2ban: the mysqld-auth jail, Access denied logging for MySQL 8 and MariaDB, log paths, plus PostgreSQL and MongoDB filters.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/monitoring/https://fail2ban.dev/guides/monitoring/Monitor fail2ban with the Prometheus exporter, Grafana, node_exporter or Zabbix, and compare GUIs and web UIs like Webmin and fail2ban-ui, with security tips.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/jellyfin/https://fail2ban.dev/guides/jellyfin/Protect Jellyfin with fail2ban: a tested filter for denied logins, log paths for native and Docker installs, the daily log file trap, DOCKER-USER bans and proxies.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/iptables/https://fail2ban.dev/guides/iptables/fail2ban's iptables actions after the 1.1.1 rewrite: multiport and allports, f2b- chains, multiple chains, ipset, DROP vs REJECT, and iptables not blocking.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/home-assistant/https://fail2ban.dev/guides/home-assistant/Protect Home Assistant with fail2ban: log failed logins, a tested filter, jails for Docker, the built-in IP ban, and what works on Home Assistant OS.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/gitea/https://fail2ban.dev/guides/gitea/Stop Git server brute force with fail2ban: a Gitea/Forgejo filter, file logging, Docker (DOCKER-USER), built-in SSH, and the stock GitLab filter in 1.1.1.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/firewalld/https://fail2ban.dev/guides/firewalld/fail2ban with firewalld: rich rules vs ipset vs multiport, zones, the fail2ban-firewalld package on Fedora and RHEL, listing bans, and firewalld is not running.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/cloudflare/https://fail2ban.dev/guides/cloudflare/Use fail2ban behind Cloudflare: restore the real visitor IP in nginx or Apache, ban at Cloudflare's edge with cloudflare-token and an API token, and handle Tunnel.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/caddy/https://fail2ban.dev/guides/caddy/Use fail2ban with Caddy: write a JSON access log, a tested filter for client_ip and status 401/403/404, a datepattern for the epoch ts field, and Docker bans.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/asterisk/https://fail2ban.dev/guides/asterisk/Stop SIP brute force with fail2ban: the asterisk filter and jail for 5060/5061 TCP+UDP, the security log, FreePBX Intrusion Detection, FreeSWITCH, Kamailio and 3CX.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/apache/https://fail2ban.dev/guides/apache/Set up fail2ban for Apache httpd/apache2: every stock apache jail explained, Debian vs RHEL log paths, the LogLevel some filters need, and a custom 404 filter.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/abuseipdb/https://fail2ban.dev/guides/abuseipdb/Report fail2ban bans to AbuseIPDB: API key setup, categories per jail, which jails to report, rate limits, keeping log lines private, plus blocklist.de and IPThreat.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/guides/https://fail2ban.dev/guides/Step-by-step fail2ban integration guides: SSH, nginx, Apache, reverse proxies, Cloudflare, Docker, self-hosted apps, mail, VPN, firewalls and monitoring.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/filters/custom/https://fail2ban.dev/filters/custom/Write a fail2ban custom filter step by step: filter.d anatomy, failregex tags like <HOST> and <F-USER>, datepattern, ignoreregex, JSON logs and testing.Sun, 25 Oct 2026 08:00:00 +0000https://fail2ban.dev/filters/https://fail2ban.dev/filters/All 96 built-in fail2ban filters in one searchable list: sshd, nginx, Apache, Postfix, Dovecot, recidive and more, with regexes and sample log lines.Sun, 25 Oct 2026 08:00:00 +0000