我在两台 Centos7 机器上安装了 fail2ban，我想用它来保护 SSH（SSH 保护似乎处于活动状态），将允许的 pw-fails 设置为 5，并将禁止时间设置为 3600 秒。我多次尝试使用假密码登录我的帐户，但仍然没有被禁止。我是否遗漏了什么？我需要为 ldap-users 进行特定设置吗？
#
# WARNING: heavily refactored in 0.9.0 release. Please review and
# customize settings for your setup.
#
# Changes: in most of the cases you should not modify this
# file, but provide customizations in jail.local file,
# or separate .conf files under jail.d/ directory, e.g.:
#
# HOW TO ACTIVATE JAILS:
#
# YOU SHOULD NOT MODIFY THIS FILE.
#
# It will probably be overwritten or improved in a distribution update.
#
# Provide customizations in a jail.local file or a jail.d/customisation.local.
# For example to change the default bantime for all jails and to enable the
# ssh-iptables jail the following (uncommented) would appear in the .local file.
# See man 5 jail.conf for details.
#
# [DEFAULT]
# bantime = 3600
#
# [sshd]
# enabled = true
#
# See jail.conf(5) man page for more information
# Comments: use '#' for comment lines and ';' (following a space) for inline comments
[INCLUDES]
#before = paths-distro.conf
before = paths-fedora.conf
# The DEFAULT allows a global definition of the options. They can be overridden
# in each jail afterwards.
[DEFAULT]
#
# MISCELLANEOUS OPTIONS
#
# "ignoreip" can be an IP address, a CIDR mask or a DNS host. Fail2ban will not
# ban a host which matches an address in this list. Several addresses can be
# defined using space separator.
ignoreip = 127.0.0.1/8
# External command that will take an tagged arguments to ignore, e.g. <ip>,
# and return true if the IP is to be ignored. False otherwise.
#
# ignorecommand = /path/to/command <ip>
ignorecommand =
# "bantime" is the number of seconds that a host is banned.
bantime = 3600
# A host is banned if it has generated "maxretry" during the last "findtime"
# seconds.
findtime = 600
# "maxretry" is the number of failures before a host get banned.
maxretry = 5
# "backend" specifies the backend used to get files modification.
# Available options are "pyinotify", "gamin", "polling", "systemd" and "auto".
# This option can be overridden in each jail as well.
#
# pyinotify: requires pyinotify (a file alteration monitor) to be installed.
# If pyinotify is not installed, Fail2ban will use auto.
# gamin: requires Gamin (a file alteration monitor) to be installed.
# If Gamin is not installed, Fail2ban will use auto.
# polling: uses a polling algorithm which does not require external libraries.
# systemd: uses systemd python library to access the systemd journal.
# Specifying "logpath" is not valid for this backend.
# See "journalmatch" in the jails associated filter config
# auto: will try to use the following backends, in order:
# pyinotify, gamin, polling.
#
# Note: if systemd backend is choses as the default but you enable a jail
# for which logs are present only in its own log files, specify some other
# backend for that jail (e.g. polling) and provide empty value for
# journalmatch. See https://github.com/fail2ban/fail2ban/issues/959#issuecomment-74901200
backend = auto
# "usedns" specifies if jails should trust hostnames in logs,
# warn when DNS lookups are performed, or ignore all hostnames in logs
#
# yes: if a hostname is encountered, a DNS lookup will be performed.
# warn: if a hostname is encountered, a DNS lookup will be performed,
# but it will be logged as a warning.
# no: if a hostname is encountered, will not be used for banning,
# but it will be logged as info.
usedns = warn
# "logencoding" specifies the encoding of the log files handled by the jail
# This is used to decode the lines from the log file.
# Typical examples: "ascii", "utf-8"
#
# auto: will use the system locale setting
logencoding = auto
# "enabled" enables the jails.
# By default all jails are disabled, and it should stay this way.
# Enable only relevant to your setup jails in your .local or jail.d/*.conf
#
# true: jail will be enabled and log files will get monitored for changes
# false: jail is not enabled
enabled = false
# "filter" defines the filter to use by the jail.
# By default jails have names matching their filter name
#
filter = %(__name__)s
#
# ACTIONS
#
# Some options used for actions
# Destination email address used solely for the interpolations in
# jail.{conf,local,d/*} configuration files.
destemail = root@localhost
# Sender email address used solely for some actions
sender = root@localhost
# E-mail action. Since 0.8.1 Fail2Ban uses sendmail MTA for the
# mailing. Change mta configuration parameter to mail if you want to
# revert to conventional 'mail'.
mta = sendmail
# Default protocol
protocol = tcp
# Specify chain where jumps would need to be added in iptables-* actions
chain = INPUT
# Ports to be banned
# Usually should be overridden in a particular jail
port = 0:65535
#
# Action shortcuts. To be used to define action parameter
# Default banning action (e.g. iptables, iptables-new,
# iptables-multiport, shorewall, etc) It is used to define
# action_* variables. Can be overridden globally or per
# section within jail.local file
banaction = iptables-multiport
# The simplest action to take: ban only
action_ = %(banaction)s[name=%(__name__)s, bantime="%(bantime)s", port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
# ban & send an e-mail with whois report to the destemail.
action_mw = %(banaction)s[name=%(__name__)s, bantime="%(bantime)s", port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
%(mta)s-whois[name=%(__name__)s, dest="%(destemail)s", protocol="%(protocol)s", chain="%(chain)s"]
# ban & send an e-mail with whois report and relevant log lines
# to the destemail.
action_mwl = %(banaction)s[name=%(__name__)s, bantime="%(bantime)s", port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
%(mta)s-whois-lines[name=%(__name__)s, dest="%(destemail)s", logpath=%(logpath)s, chain="%(chain)s"]
# See the IMPORTANT note in action.d/xarf-login-attack for when to use this action
#
# ban & send a xarf e-mail to abuse contact of IP address and include relevant log lines
# to the destemail.
action_xarf = %(banaction)s[name=%(__name__)s, bantime="%(bantime)s", port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
xarf-login-attack[service=%(__name__)s, sender="%(sender)s", logpath=%(logpath)s, port="%(port)s"]
# ban IP on CloudFlare & send an e-mail with whois report and relevant log lines
# to the destemail.
action_cf_mwl = cloudflare[cfuser="%(cfemail)s", cftoken="%(cfapikey)s"]
%(mta)s-whois-lines[name=%(__name__)s, dest="%(destemail)s", logpath=%(logpath)s, chain="%(chain)s"]
# Report block via blocklist.de fail2ban reporting service API
#
# See the IMPORTANT note in action.d/blocklist_de.conf for when to
# use this action. Create a file jail.d/blocklist_de.local containing
# [Init]
# blocklist_de_apikey = {api key from registration]
#
action_blocklist_de = blocklist_de[email="%(sender)s", service=%(filter)s, apikey="%(blocklist_de_apikey)s"]
# Report ban via badips.com, and use as blacklist
#
# See BadIPsAction docstring in config/action.d/badips.py for
# documentation for this action.
#
# NOTE: This action relies on banaction being present on start and therefore
# should be last action defined for a jail.
#
action_badips = badips.py[category="%(name)s", banaction="%(banaction)s"]
# Choose default action. To change, just override value of 'action' with the
# interpolation to the chosen action shortcut (e.g. action_mw, action_mwl, etc) in jail.local
# globally (section [DEFAULT]) or per specific section
action = %(action_)s
#
# JAILS
#
#
# SSH servers
#
[sshd]
port = 2431
logpath = %(sshd_log)s
[sshd-ddos]
# This jail corresponds to the standard configuration in Fail2ban.
# The mail-whois action send a notification e-mail with a whois request
# in the body.
port = ssh
logpath = %(sshd_log)s
[dropbear]
port = ssh
logpath = %(dropbear_log)s
[selinux-ssh]
port = ssh
logpath = %(auditd_log)s
maxretry = 5
#
# HTTP servers
#
[apache-auth]
port = http,https
logpath = %(apache_error_log)s
[apache-badbots]
# Ban hosts which agent identifies spammer robots crawling the web
# for email addresses. The mail outputs are buffered.
port = http,https
logpath = %(apache_access_log)s
bantime = 172800
maxretry = 1
[apache-noscript]
port = http,https
logpath = %(apache_error_log)s
maxretry = 6
[apache-overflows]
port = http,https
logpath = %(apache_error_log)s
maxretry = 2
[apache-nohome]
port = http,https
logpath = %(apache_error_log)s
maxretry = 2
[apache-botsearch]
port = http,https
logpath = %(apache_error_log)s
maxretry = 2
[apache-fakegooglebot]
port = http,https
logpath = %(apache_access_log)s
maxretry = 1
ignorecommand = %(ignorecommands_dir)s/apache-fakegooglebot <ip>
[apache-modsecurity]
port = http,https
logpath = %(apache_error_log)s
maxretry = 2
[apache-shellshock]
port = http,https
logpath = %(apache_error_log)s
maxretry = 1
[nginx-http-auth]
port = http,https
logpath = %(nginx_error_log)s
[nginx-botsearch]
port = http,https
logpath = %(nginx_error_log)s
maxretry = 2
# Ban attackers that try to use PHP's URL-fopen() functionality
# through GET/POST variables. - Experimental, with more than a year
# of usage in production environments.
[php-url-fopen]
port = http,https
logpath = %(nginx_access_log)s
%(apache_access_log)s
[suhosin]
port = http,https
logpath = %(suhosin_log)s
[lighttpd-auth]
# Same as above for Apache's mod_auth
# It catches wrong authentifications
port = http,https
logpath = %(lighttpd_error_log)s
#
# Webmail and groupware servers
#
[roundcube-auth]
port = http,https
logpath = logpath = %(roundcube_errors_log)s
[openwebmail]
port = http,https
logpath = /var/log/openwebmail.log
[horde]
port = http,https
logpath = /var/log/horde/horde.log
[groupoffice]
port = http,https
logpath = /home/groupoffice/log/info.log
[sogo-auth]
# Monitor SOGo groupware server
# without proxy this would be:
# port = 20000
port = http,https
logpath = /var/log/sogo/sogo.log
[tine20]
logpath = /var/log/tine20/tine20.log
port = http,https
maxretry = 5
#
# Web Applications
#
#
[drupal-auth]
port = http,https
logpath = %(syslog_daemon)s
[guacamole]
port = http,https
logpath = /var/log/tomcat*/catalina.out
[monit]
#Ban clients brute-forcing the monit gui login
filter = monit
port = 2812
logpath = /var/log/monit
[webmin-auth]
port = 10000
logpath = %(syslog_authpriv)s
[froxlor-auth]
port = http,https
logpath = %(syslog_authpriv)s
#
# HTTP Proxy servers
#
#
[squid]
port = 80,443,3128,8080
logpath = /var/log/squid/access.log
[3proxy]
port = 3128
logpath = /var/log/3proxy.log
#
# FTP servers
#
[proftpd]
port = ftp,ftp-data,ftps,ftps-data
logpath = %(proftpd_log)s
[pure-ftpd]
port = ftp,ftp-data,ftps,ftps-data
logpath = %(pureftpd_log)s
maxretry = 6
[gssftpd]
port = ftp,ftp-data,ftps,ftps-data
logpath = %(syslog_daemon)s
maxretry = 6
[wuftpd]
port = ftp,ftp-data,ftps,ftps-data
logpath = %(wuftpd_log)s
maxretry = 6
[vsftpd]
# or overwrite it in jails.local to be
# logpath = %(syslog_authpriv)s
# if you want to rely on PAM failed login attempts
# vsftpd's failregex should match both of those formats
port = ftp,ftp-data,ftps,ftps-data
logpath = %(vsftpd_log)s
#
# Mail servers
#
# ASSP SMTP Proxy Jail
[assp]
port = smtp,465,submission
logpath = /root/path/to/assp/logs/maillog.txt
[courier-smtp]
port = smtp,465,submission
logpath = %(syslog_mail)s
[postfix]
port = smtp,465,submission
logpath = %(postfix_log)s
[postfix-rbl]
port = smtp,465,submission
logpath = %(syslog_mail)s
maxretry = 1
[sendmail-auth]
port = submission,465,smtp
logpath = %(syslog_mail)s
[sendmail-reject]
port = smtp,465,submission
logpath = %(syslog_mail)s
[qmail-rbl]
filter = qmail
port = smtp,465,submission
logpath = /service/qmail/log/main/current
# dovecot defaults to logging to the mail syslog facility
# but can be set by syslog_facility in the dovecot configuration.
[dovecot]
port = pop3,pop3s,imap,imaps,submission,465,sieve
logpath = %(dovecot_log)s
[sieve]
port = smtp,465,submission
logpath = %(dovecot_log)s
[solid-pop3d]
port = pop3,pop3s
logpath = %(solidpop3d_log)s
[exim]
port = smtp,465,submission
logpath = %(exim_main_log)s
[exim-spam]
port = smtp,465,submission
logpath = %(exim_main_log)s
[kerio]
port = imap,smtp,imaps,465
logpath = /opt/kerio/mailserver/store/logs/security.log
#
# Mail servers authenticators: might be used for smtp,ftp,imap servers, so
# all relevant ports get banned
#
[courier-auth]
port = smtp,465,submission,imap3,imaps,pop3,pop3s
logpath = %(syslog_mail)s
[postfix-sasl]
port = smtp,465,submission,imap3,imaps,pop3,pop3s
# You might consider monitoring /var/log/mail.warn instead if you are
# running postfix since it would provide the same log lines at the
# "warn" level but overall at the smaller filesize.
logpath = %(postfix_log)s
[perdition]
port = imap3,imaps,pop3,pop3s
logpath = %(syslog_mail)s
[squirrelmail]
port = smtp,465,submission,imap2,imap3,imaps,pop3,pop3s,http,https,socks
logpath = /var/lib/squirrelmail/prefs/squirrelmail_access_log
[cyrus-imap]
port = imap3,imaps
logpath = %(syslog_mail)s
[uwimap-auth]
port = imap3,imaps
logpath = %(syslog_mail)s
#
#
# DNS servers
#
# !!! WARNING !!!
# Since UDP is connection-less protocol, spoofing of IP and imitation
# of illegal actions is way too simple. Thus enabling of this filter
# might provide an easy way for implementing a DoS against a chosen
# victim. See
# http://nion.modprobe.de/blog/archives/690-fail2ban-+-dns-fail.html
# Please DO NOT USE this jail unless you know what you are doing.
#
# IMPORTANT: see filter.d/named-refused for instructions to enable logging
# This jail blocks UDP traffic for DNS requests.
# [named-refused-udp]
#
# filter = named-refused
# port = domain,953
# protocol = udp
# logpath = /var/log/named/security.log
# IMPORTANT: see filter.d/named-refused for instructions to enable logging
# This jail blocks TCP traffic for DNS requests.
[named-refused]
port = domain,953
logpath = /var/log/named/security.log
[nsd]
port = 53
action = %(banaction)s[name=%(__name__)s-tcp, port="%(port)s", protocol="tcp", chain="%(chain)s", actname=%(banaction)s-tcp]
%(banaction)s[name=%(__name__)s-udp, port="%(port)s", protocol="udp", chain="%(chain)s", actname=%(banaction)s-udp]
logpath = /var/log/nsd.log
#
# Miscellaneous
#
[asterisk]
port = 5060,5061
action = %(banaction)s[name=%(__name__)s-tcp, port="%(port)s", protocol="tcp", chain="%(chain)s", actname=%(banaction)s-tcp]
%(banaction)s[name=%(__name__)s-udp, port="%(port)s", protocol="udp", chain="%(chain)s", actname=%(banaction)s-udp]
%(mta)s-whois[name=%(__name__)s, dest="%(destemail)s"]
logpath = /var/log/asterisk/messages
maxretry = 10
[freeswitch]
port = 5060,5061
action = %(banaction)s[name=%(__name__)s-tcp, port="%(port)s", protocol="tcp", chain="%(chain)s", actname=%(banaction)s-tcp]
%(banaction)s[name=%(__name__)s-udp, port="%(port)s", protocol="udp", chain="%(chain)s", actname=%(banaction)s-udp]
%(mta)s-whois[name=%(__name__)s, dest="%(destemail)s"]
logpath = /var/log/freeswitch.log
maxretry = 10
# To log wrong MySQL access attempts add to /etc/my.cnf in [mysqld] or
# equivalent section:
# log-warning = 2
#
# for syslog (daemon facility)
# [mysqld_safe]
# syslog
#
# for own logfile
# [mysqld]
# log-error=/var/log/mysqld.log
[mysqld-auth]
port = 3306
logpath = %(mysql_log)s
maxretry = 5
# Jail for more extended banning of persistent abusers
# !!! WARNINGS !!!
# 1. Make sure that your loglevel specified in fail2ban.conf/.local
# is not at DEBUG level -- which might then cause fail2ban to fall into
# an infinite loop constantly feeding itself with non-informative lines
# 2. Increase dbpurgeage defined in fail2ban.conf to e.g. 648000 (7.5 days)
# to maintain entries for failed logins for sufficient amount of time
[recidive]
logpath = /var/log/fail2ban.log
banaction = iptables-allports
bantime = 604800 ; 1 week
findtime = 86400 ; 1 day
maxretry = 5
# Generic filter for PAM. Has to be used with action which bans all
# ports such as iptables-allports, shorewall
[pam-generic]
# pam-generic filter can be customized to monitor specific subset of 'tty's
banaction = iptables-allports
logpath = %(syslog_authpriv)s
[xinetd-fail]
banaction = iptables-multiport-log
logpath = %(syslog_daemon)s
maxretry = 2
# stunnel - need to set port for this
[stunnel]
logpath = /var/log/stunnel4/stunnel.log
[ejabberd-auth]
port = 5222
logpath = /var/log/ejabberd/ejabberd.log
[counter-strike]
logpath = /opt/cstrike/logs/L[0-9]*.log
# Firewall: http://www.cstrike-planet.com/faq/6
tcpport = 27030,27031,27032,27033,27034,27035,27036,27037,27038,27039
udpport = 1200,27000,27001,27002,27003,27004,27005,27006,27007,27008,27009,27010,27011,27012,27013,27014,27015
action = %(banaction)s[name=%(__name__)s-tcp, port="%(tcpport)s", protocol="tcp", chain="%(chain)s", actname=%(banaction)s-tcp]
%(banaction)s[name=%(__name__)s-udp, port="%(udpport)s", protocol="udp", chain="%(chain)s", actname=%(banaction)s-udp]
# consider low maxretry and a long bantime
# nobody except your own Nagios server should ever probe nrpe
[nagios]
enabled = false
logpath = %(syslog_daemon)s ; nrpe.cfg may define a different log_facility
maxretry = 1
[oracleims]
# see "oracleims" filter file for configuration requirement for Oracle IMS v6 and above
enabled = false
logpath = /opt/sun/comms/messaging64/log/mail.log_current
maxretry = 6
banaction = iptables-allports
[directadmin]
enabled = false
logpath = /var/log/directadmin/login.log
port = 2222
[portsentry]
enabled = false
logpath = /var/lib/portsentry/portsentry.history
maxretry = 1
[pass2allow-ftp]
# this pass2allow example allows FTP traffic after successful HTTP authentication
port = ftp,ftp-data,ftps,ftps-data
# knocking_url variable must be overridden to some secret value in filter.d/apache-pass.local
filter = apache-pass
# access log of the website with HTTP auth
logpath = %(apache_access_log)s
blocktype = RETURN
returntype = DROP
bantime = 3600
maxretry = 1
findtime = 1
编辑1：
所以我尝试了下面评论中提到的所有方法，但对我来说没有用。我尝试将必要的配置放入 jail.local 中，并将其与默认 jail.conf 一起使用。这没有用。“假攻击者”甚至没有被关进 fail2ban 的监狱里。
使用 jail.conf 中的当前配置
[sshd]
enabled = true
port = 1234
logpath = %(sshd_log)s
[sshd-ddos]
# This jail corresponds to the standard configuration in Fail2ban.
# The mail-whois action send a notification e-mail with a whois request
# in the body.
port = ssh
logpath = %(sshd_log)s
袭击者被送进监狱：
fail2ban-client status sshd
Status for the jail: sshd
|- Filter
| |- Currently failed: 0
| |- Total failed: 1
| `- File list: /var/log/secure
`- Actions
|- Currently banned: 1
|- Total banned: 1
`- Banned IP list: 192.168.1.1
但即使如此，iptables 本身并没有发生任何变化：
iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT udp -- anywhere anywhere udp dpt:domain
ACCEPT tcp -- anywhere anywhere tcp dpt:domain
ACCEPT udp -- anywhere anywhere udp dpt:bootps
ACCEPT tcp -- anywhere anywhere tcp dpt:bootps
Chain FORWARD (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere 192.168.122.0/24 ctstate RELATED,ESTABLISHED
ACCEPT all -- 192.168.122.0/24 anywhere
ACCEPT all -- anywhere anywhere
REJECT all -- anywhere anywhere reject-with icmp-port-unreachable
REJECT all -- anywhere anywhere reject-with icmp-port-unreachable
Chain OUTPUT (policy ACCEPT)
target prot opt source destination
ACCEPT udp -- anywhere anywhere udp dpt:bootpc
被禁止的攻击者仍然可以无问题地登录（被禁止期间）。
有人知道如何解决这个问题吗？
答案1
于是我找到了问题所在。Centos 中的 Fail2ban 默认使用防火墙作为阻止 IP 的工具。但是防火墙已关闭，因此 fail2ban 执行的命令没有任何作用。
为了使其与 iptables 一起工作，需要在 jail.local 中设置必要的命令。
action = iptables[name=SSH, port=ssh, protocol=tcp]
并且它有效。
谢谢您的帮助 ：）
答案2
看来你的 jail.conf 中没有启用 sshd jail。你应该取消注释这两行以启用它
# [sshd]
# enabled = true
如果这不能解决问题，请在评论中发布此命令的结果：
fail2ban-client status
fail2ban-client status ssh
谢谢。