Denyhosts is another utility similar to fail2ban. It parses log files toidentify potential attacks against SSH services. A clear advantage thatDenyhosts has over fail2ban is the synchronisation mechanism sinceversion 2.0. Denyhostspermits communication with a central server to exchange informationabout denied hosts by other Denyhosts daemons. However unlike fail2ban,it does not modify any firewall (iptables) rules, instead it relies ontcpwrapper and the hosts.deny file to block ssh access.
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