What it does
Fail2ban monitors logs for configured failure patterns and updates firewall rules to temporarily block matching source addresses.
Fail2ban joins two parts of a defensive workflow: a log pattern and a firewall action. Its README describes temporary bans after repeated authentication failures, with filters for services such as SSH and Apache. Confirm that the service's actual log format matches the filter before enabling a jail. Keep authorized administration paths available while evaluating bans. The project explicitly warns that reducing repeated guesses does not remove the risk of weak authentication.
Strengths
- Configurable log-pattern and firewall-response workflow
Watch out for
- Rate reduction does not eliminate weak-authentication risk
Best for
- Administrators reducing repeated service-authentication attempts