DenyHosts and Fail2ban are types of what security tool?

DenyHosts and Fail2ban are categorized as Intrusion Detection Systems (IDS) because they are designed to monitor and analyze system logs and network traffic for suspicious activities, particularly related to unauthorized access attempts. Their primary function is to detect patterns that signify potential attacks, such as repeated failed login attempts, and respond by blocking those malicious IP addresses.

By actively monitoring these events, DenyHosts and Fail2ban contribute to the security of a Linux system by preventing brute-force attacks on SSH and other services. They automatically update firewall rules or take other actions to mitigate risks, illustrating their role in identifying and responding to intrusions in a proactive manner. This makes them distinct from firewalls, which primarily enforce policies to block or allow traffic based on predetermined rules, and from anti-virus software, which focuses mainly on detecting and removing malware. Network monitoring tools, while relevant to security, typically focus on analyzing traffic patterns and performance rather than specifically preventing unauthorized access attempts like DenyHosts and Fail2ban do.