# fail2ban/fail2ban

Daemon to ban hosts that cause multiple authentication errors

Repository: https://github.com/fail2ban/fail2ban
Canonical: https://ross.abutalabs.com/products/fail2ban
Homepage: http://www.fail2ban.org
Language: Python
License: NOASSERTION
License Family: other
Topics: linux, macos, security, intrusion-prevention, fail2ban, bsd, gplv2, python, ban-hosts, intrusion-detection, ids, ips, anti-bot, attack-prevention, hids, security-tools, loganalyzer, monitoring, ban-management
Last push: 2026-08-26T14:06:18+00:00

## Health v2 (maintenance only)
Score: 88/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 66, longevity 100
- inputs: {"age_days": 5453, "days_push": 7, "days_rel": 18, "gap_med": null, "n_releases_24m": 1}
- flags: no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 18479, forks 1497 (observed 2026-08-28T04:11:26.718225+00:00)

## What it is
Fail2ban is a Python daemon that scans log files for repeated authentication failures and bans offending IP addresses by updating firewall rules for a configurable period. It ships with filters for common services like sshd and Apache and can be configured to monitor arbitrary log files.

## Use cases
- block brute-force SSH login attempts
- automatically ban IPs with too many failed logins
- protect a web server from repeated auth errors
- monitor log files and update firewall rules
- reduce bot and attacker traffic on a self-hosted server
- set up intrusion prevention on a Linux VPS

## When to choose
- you run an internet-exposed server (SSH, web, mail) and want automatic banning of abusive hosts
- you want a mature, widely packaged tool that works with existing firewall backends
- you need configurable filters for custom log files and error patterns
- you need IPv6 support for banning

## When to avoid
- you need to eliminate weak authentication entirely - fail2ban only reduces the rate of bad attempts, so use 2FA or key-based auth as well
- you are on a platform without firewall control or log files it can watch
- you need a full IDS/IPS with deep packet inspection rather than log-based banning

## Facets
- artifact type: service
- maturity: stable
- function: security, monitoring, logging, cli
- domain: security, self-hosted, networking
- platform: bsd, python, cli
- tags: intrusion-prevention, fail2ban, log-parsing, firewall, brute-force-protection, ids, ips, daemon, devops, linux, macos

## Member repositories
- fail2ban/fail2ban (main) score 88

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:26.718225+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:02:02.028710+00:00, confidence not recorded.
  - readme: https://github.com/fail2ban/fail2ban (fetched 2026-08-28T04:11:26.718225+00:00, sha 6faec51da15b)
  - homepage: http://www.fail2ban.org (fetched 2026-08-29T07:59:37.780606+00:00, sha ce2bd591c1d4)
- Data as of 2026-08-30T08:39:29.467469+00:00.