{"id":"linuxserver-fail2ban","name":"fail2ban","homepage":"https://hub.docker.com/r/linuxserver/fail2ban","repo_url":"https://hub.docker.com/r/linuxserver/fail2ban","category":"security","subcategories":[],"tags":["security","intrusion-prevention","firewall","log-monitoring","sysadmin","linux","self-hosted"],"what_it_does":"Fail2ban is a host-based intrusion prevention tool that monitors log files (e.g., for SSH failures) and automatically bans IP addresses that match configured patterns/rules, using configurable ban actions and whitelists.","use_cases":["Reduce brute-force and repeated failed login attempts against SSH and other network services by auto-banning offending IPs","Harden servers by responding to repeated suspicious activity in application/service logs","Complement firewall rules with log-driven, per-service ban policies","Mitigate scanning/noisy traffic by temporarily banning sources that trigger configured detectors"],"not_for":["As a cloud-managed/SaaS security product (it runs on your infrastructure)","Detecting application-level fraud or complex behavioral threats without appropriate log patterns/actions","Replacing endpoint/WAF protections or full security monitoring/SIEM in high-compliance environments","Use cases requiring a hosted REST/GraphQL API for interactive queries"],"best_when":"You can reliably produce actionable logs, have shell access to configure the daemon, and want automated, log-driven IP banning on one or more servers.","avoid_when":"You cannot modify firewall/security policy or tolerate the risk of banning legitimate users due to misconfigured regexes or NAT/proxy-heavy traffic.","alternatives":["SSHGuard","CrowdSec","iptables/nftables with external automation","OSSEC/Wazuh (for broader host monitoring/response)","Using a reverse proxy/WAF with built-in rate limiting/bot protection"],"af_score":31.8,"security_score":59.0,"reliability_score":45.0,"package_type":"mcp_server","discovery_source":["docker_mcp"],"priority":"high","status":"evaluated","version_evaluated":null,"last_evaluated":"2026-03-30T15:20:03.395735+00:00","interface":{"has_rest_api":false,"has_graphql":false,"has_grpc":false,"has_mcp_server":false,"mcp_server_url":null,"has_sdk":false,"sdk_languages":[],"openapi_spec_url":null,"webhooks":false},"auth":{"methods":["Config-based daemon deployment on host (typically no per-user API auth); operational access via OS privileges"],"oauth":false,"scopes":false,"notes":"There is no external API authentication model like API keys/OAuth; instead, access is governed by who can edit Fail2ban configuration and manage the process on the host (typically root/privileged access)."},"pricing":{"model":null,"free_tier_exists":false,"free_tier_limits":null,"paid_tiers":[],"requires_credit_card":false,"estimated_workload_costs":null,"notes":"Open-source, self-hosted; costs are operational (compute/storage/maintenance), not usage-based pricing."},"requirements":{"requires_signup":false,"requires_credit_card":false,"domain_verification":false,"data_residency":[],"compliance":[],"min_contract":null},"agent_readiness":{"af_score":31.8,"security_score":59.0,"reliability_score":45.0,"mcp_server_quality":0.0,"documentation_accuracy":30.0,"error_message_quality":0.0,"error_message_notes":null,"auth_complexity":90.0,"rate_limit_clarity":10.0,"tls_enforcement":70.0,"auth_strength":55.0,"scope_granularity":45.0,"dependency_hygiene":55.0,"secret_handling":70.0,"security_notes":"Security properties depend on correct firewall/banning configuration and on the safety of regexes and actions. Fail2ban typically interacts with the local firewall and uses host privileges; it does not provide an external API auth layer. Misconfiguration can cause denial-of-service to legitimate users (false positives), especially behind NAT/load balancers. Ensure least-privilege where possible and review jail/action settings.","uptime_documented":0.0,"version_stability":70.0,"breaking_changes_history":60.0,"error_recovery":50.0,"idempotency_support":"false","idempotency_notes":null,"pagination_style":"none","retry_guidance_documented":false,"known_agent_gotchas":["Fail2ban is log-driven and stateful; an agent changing configs should consider how bans/unbans are managed over time.","Rules/patterns are highly environment-specific (log formats, service names, jail/action choices).","If logs are missing/rotated unexpectedly or regexes are wrong, the system may not trigger bans or may ban incorrectly."]}}