設定 Fail2Ban 阻絕暴力破解 dovecot / sendmail / bind / openvpn / ssh / apache 方式 [蔡宗融個人網站]
/var/log/secure 內出現類似以下的訊息: Jun 3 16:31:55 hp-mail saslauthd[3356]: pam_unix(smtp:auth): authentication failure; logname= uid=0 euid=0 tty= ruser= rhost= user=everstar Jun 3 16:32:06 hp-mail saslauthd[3357]: pam_unix(smtp:auth): authentication ......