fail2ban iptables having port 22 and fails to block ssh on custom port

13,613

Solution 1

Since you are using ssh as port name it is going to search on /etc/services file and map the name ssh to the associated port which is 22

You can simply modify the /etc/services file and change port 22/tcp to whatever you like.

Save changes and you are done!

Solution 2

You have to change the default port in the action line, something like this:

[ssh-iptables]

enabled  = true
filter   = sshd
action   = iptables[name=SSH, port=12345, protocol=tcp]
           sendmail-whois[name=SSH, dest=root, [email protected]]
logpath  = /var/log/secure
maxretry = 5

Don't forget to restart the fail2ban after that.

Solution 3

Copy paste from my /etc/fail2ban/jail.local Works fine and let me change on one place for both TCP/22 and TCP/2222

[ssh]
enabled = true
port = ssh,2222
filter = sshd
logpath = /var/log/auth.log
maxretry = 4
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Ergec
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Ergec

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Updated on September 18, 2022

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  • Ergec
    Ergec almost 2 years

    This question is almost same problem like mine but accepted answer doesn't solve my issues

    In Fail2Ban, How to Change the SSH port number?

    SSH on port 22 everything works great. After 5 attempts fail2ban reads from logs and bans my ip for 600 seconds. And here is fail2ban log

    2013-07-10 11:54:08,522 fail2ban.actions: WARNING [ssh-iptables] Ban 192.168.162.191
    2013-07-10 12:04:09,348 fail2ban.actions: WARNING [ssh-iptables] Unban 192.168.162.191
    

    My iptables, fail2ban has port 22

    Chain INPUT (policy ACCEPT 1591 packets, 165K bytes)
     pkts bytes target     prot opt in     out     source               destination
       44  5292 fail2ban-SSH  tcp  --  *      *       0.0.0.0/0            0.0.0.0/0           tcp dpt:22
    
    Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
     pkts bytes target     prot opt in     out     source               destination
    
    Chain OUTPUT (policy ACCEPT 181 packets, 71152 bytes)
     pkts bytes target     prot opt in     out     source               destination
    
    Chain fail2ban-SSH (1 references)
     pkts bytes target     prot opt in     out     source               destination
       35  4836 RETURN     all  --  *      *       0.0.0.0/0            0.0.0.0/0
    

    I change SSH port to let say 12345 by editing ssh config

    vi /etc/ssh/sshd_config
    service sshd restart
    

    Now ssh works on port 12345 not 22, totally fine

    Logs show my failed login attempts properly

    After 5 attempts fail2ban log file displays ban

    2013-07-10 11:37:33,124 fail2ban.actions: WARNING [ssh-iptables] Ban 192.168.162.191
    

    PROBLEM IS

    But it never bans me from SSH port 12345, I can still access ssh and login

    I believe this is because iptables has rule for fail2ban on port 22 but not sure how to edit it. Because if I restart fail2ban it adds it's own rule again with port 22

    EDIT 1:

    jail.conf

    # Fail2Ban jail specifications file
    #
    # Comments: use '#' for comment lines and ';' (following a space) for inline comments
    #
    # Changes:  in most of the cases you should not modify this
    #           file, but provide customizations in jail.local file, e.g.:
    #
    # [DEFAULT]
    # bantime = 3600
    #
    # [ssh-iptables]
    # enabled = true
    #
    
    # The DEFAULT allows a global definition of the options. They can be overridden
    # in each jail afterwards.
    
    [DEFAULT]
    
    # "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
    
    # "bantime" is the number of seconds that a host is banned.
    bantime  = 600
    
    # 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 = 3
    
    # "backend" specifies the backend used to get files modification.
    # Available options are "pyinotify", "gamin", "polling" 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.
    # auto:      will try to use the following backends, in order:
    #              pyinotify, gamin, polling.
    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
    
    
    # This jail corresponds to the standard configuration in Fail2ban 0.6.
    # The mail-whois action send a notification e-mail with a whois request
    # in the body.
    
    [ssh-iptables]
    
    enabled  = true
    filter   = sshd
    port     = ssh #TRIED TO PUT HERE 12345 port number but problem persists
    action   = iptables[name=SSH, port=ssh, protocol=tcp]
               sendmail-whois[name=SSH, dest=root, [email protected]]
    logpath  = /var/log/secure
    maxretry = 5
    
    [proftpd-iptables]
    
    enabled  = false
    filter   = proftpd
    action   = iptables[name=ProFTPD, port=ftp, protocol=tcp]
               sendmail-whois[name=ProFTPD, [email protected]]
    logpath  = /var/log/proftpd/proftpd.log
    maxretry = 6
    
    # This jail forces the backend to "polling".
    
    [sasl-iptables]
    
    enabled  = false
    filter   = sasl
    backend  = polling
    action   = iptables[name=sasl, port=smtp, protocol=tcp]
               sendmail-whois[name=sasl, [email protected]]
    logpath  = /var/log/mail.log
    
    # ASSP SMTP Proxy Jail
    [assp]
    enabled  = false
    filter   = assp
    action = iptables-multiport[name=assp,port="25,465,587"]
    logpath  = /root/path/to/assp/logs/maillog.txt
    
    # Here we use TCP-Wrappers instead of Netfilter/Iptables. "ignoreregex" is
    # used to avoid banning the user "myuser".
    
    [ssh-tcpwrapper]
    
    enabled     = false
    filter      = sshd
    action      = hostsdeny
                  sendmail-whois[name=SSH, [email protected]]
    ignoreregex = for myuser from
    logpath     = /var/log/sshd.log
    
    # Here we use blackhole routes for not requiring any additional kernel support
    # to store large volumes of banned IPs
    
    [ssh-route]
    
    enabled = false
    filter = sshd
    action = route
    logpath = /var/log/sshd.log
    maxretry = 5
    
    # Here we use a combination of Netfilter/Iptables and IPsets
    # for storing large volumes of banned IPs
    #
    # IPset comes in two versions. See ipset -V for which one to use
    # requires the ipset package and kernel support.
    [ssh-iptables-ipset4]
    
    enabled  = false
    filter   = sshd
    action   = iptables-ipset-proto4[name=SSH, port=ssh, protocol=tcp]
    logpath  = /var/log/sshd.log
    maxretry = 5
    
    [ssh-iptables-ipset6]
    enabled  = false
    filter   = sshd
    action   = iptables-ipset-proto6[name=SSH, port=ssh, protocol=tcp, bantime=600]
    logpath  = /var/log/sshd.log
    maxretry = 5
    
    # bsd-ipfw is ipfw used by BSD. It uses ipfw tables.
    # table number must be unique.
    # 
    # This will create a deny rule for that table ONLY if a rule 
    # for the table doesn't ready exist.
    #
    [ssh-bsd-ipfw]
    enabled  = false
    filter   = sshd
    action   = bsd-ipfw[port=ssh,table=1]
    logpath  = /var/log/auth.log
    maxretry = 5
    
    # This jail demonstrates the use of wildcards in "logpath".
    # Moreover, it is possible to give other files on a new line.
    
    [apache-tcpwrapper]
    
    enabled  = false
    filter   = apache-auth
    action   = hostsdeny
    logpath  = /var/log/apache*/*error.log
               /home/www/myhomepage/error.log
    maxretry = 6
    
    # The hosts.deny path can be defined with the "file" argument if it is
    # not in /etc.
    
    [postfix-tcpwrapper]
    
    enabled  = false
    filter   = postfix
    action   = hostsdeny[file=/not/a/standard/path/hosts.deny]
               sendmail[name=Postfix, [email protected]]
    logpath  = /var/log/postfix.log
    bantime  = 300
    
    # Do not ban anybody. Just report information about the remote host.
    # A notification is sent at most every 600 seconds (bantime).
    
    [vsftpd-notification]
    
    enabled  = false
    filter   = vsftpd
    action   = sendmail-whois[name=VSFTPD, [email protected]]
    logpath  = /var/log/vsftpd.log
    maxretry = 5
    bantime  = 1800
    
    # Same as above but with banning the IP address.
    
    [vsftpd-iptables]
    
    enabled  = false
    filter   = vsftpd
    action   = iptables[name=VSFTPD, port=ftp, protocol=tcp]
               sendmail-whois[name=VSFTPD, [email protected]]
    logpath  = /var/log/vsftpd.log
    maxretry = 5
    bantime  = 1800
    
    # Ban hosts which agent identifies spammer robots crawling the web
    # for email addresses. The mail outputs are buffered.
    
    [apache-badbots]
    
    enabled  = false
    filter   = apache-badbots
    action   = iptables-multiport[name=BadBots, port="http,https"]
               sendmail-buffered[name=BadBots, lines=5, [email protected]]
    logpath  = /var/www/*/logs/access_log
    bantime  = 172800
    maxretry = 1
    
    # Use shorewall instead of iptables.
    
    [apache-shorewall]
    
    enabled  = false
    filter   = apache-noscript
    action   = shorewall
               sendmail[name=Postfix, [email protected]]
    logpath  = /var/log/apache2/error_log
    
    # Monitor roundcube server
    
    [roundcube-iptables]
    
    enabled  = false
    filter   = roundcube-auth
    action   = iptables[name=RoundCube, port="http,https"]
    logpath  = /var/log/roundcube/userlogins
    
    
    # Monitor SOGo groupware server
    
    [sogo-iptables]
    
    enabled  = false
    filter   = sogo-auth
    # without proxy this would be:
    # port    = 20000
    action   = iptables[name=SOGo, port="http,https"]
    logpath  = /var/log/sogo/sogo.log
    
    # 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]
    
    enabled = false
    action  = iptables[name=php-url-open, port="http,https"]
    filter  = php-url-fopen
    logpath = /var/www/*/logs/access_log
    maxretry = 1
    
    # A simple PHP-fastcgi jail which works with lighttpd.
    # If you run a lighttpd server, then you probably will
    # find these kinds of messages in your error_log:
    # ALERT – tried to register forbidden variable ‘GLOBALS’
    # through GET variables (attacker '1.2.3.4', file '/var/www/default/htdocs/index.php')
    # This jail would block the IP 1.2.3.4.
    
    [lighttpd-fastcgi]
    
    enabled = false
    filter  = lighttpd-fastcgi
    action  = iptables[name=lighttpd-fastcgi, port="http,https"]
    # adapt the following two items as needed
    logpath = /var/log/lighttpd/error.log
    maxretry = 2
    
    # Same as above for mod_auth
    # It catches wrong authentications
    
    [lighttpd-auth]
    
    enabled = false
    filter  = lighttpd-auth
    action  = iptables[name=lighttpd-auth, port="http,https"]
    # adapt the following two items as needed
    logpath = /var/log/lighttpd/error.log
    maxretry = 2
    
    # This jail uses ipfw, the standard firewall on FreeBSD. The "ignoreip"
    # option is overridden in this jail. Moreover, the action "mail-whois" defines
    # the variable "name" which contains a comma using "". The characters '' are
    # valid too.
    
    [ssh-ipfw]
    
    enabled  = false
    filter   = sshd
    action   = ipfw[localhost=192.168.0.1]
               sendmail-whois[name="SSH,IPFW", [email protected]]
    logpath  = /var/log/auth.log
    ignoreip = 168.192.0.1
    
    # These jails block attacks against named (bind9). By default, logging is off
    # with bind9 installation. You will need something like this:
    #
    # logging {
    #     channel security_file {
    #         file "/var/log/named/security.log" versions 3 size 30m;
    #         severity dynamic;
    #         print-time yes;
    #     };
    #     category security {
    #         security_file;
    #     };
    # };
    #
    # in your named.conf to provide proper logging.
    # This jail blocks UDP traffic for DNS requests.
    
    # !!! 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.
    #
    # [named-refused-udp]
    #
    # enabled  = false
    # filter   = named-refused
    # action   = iptables-multiport[name=Named, port="domain,953", protocol=udp]
    #            sendmail-whois[name=Named, [email protected]]
    # logpath  = /var/log/named/security.log
    # ignoreip = 168.192.0.1
    
    # This jail blocks TCP traffic for DNS requests.
    
    [named-refused-tcp]
    
    enabled  = false
    filter   = named-refused
    action   = iptables-multiport[name=Named, port="domain,953", protocol=tcp]
               sendmail-whois[name=Named, [email protected]]
    logpath  = /var/log/named/security.log
    ignoreip = 168.192.0.1
    
    # Multiple jails, 1 per protocol, are necessary ATM:
    # see https://github.com/fail2ban/fail2ban/issues/37
    [asterisk-tcp]
    
    enabled  = false
    filter   = asterisk
    action   = iptables-multiport[name=asterisk-tcp, port="5060,5061", protocol=tcp]
               sendmail-whois[name=Asterisk, [email protected], [email protected]]
    logpath  = /var/log/asterisk/messages
    maxretry = 10
    
    [asterisk-udp]
    
    enabled  = false
    filter   = asterisk
    action   = iptables-multiport[name=asterisk-udp, port="5060,5061", protocol=udp]
               sendmail-whois[name=Asterisk, [email protected], [email protected]]
    logpath  = /var/log/asterisk/messages
    maxretry = 10
    
    # To log wrong MySQL access attempts add to /etc/my.cnf:
    # log-error=/var/log/mysqld.log
    # log-warning = 2
    [mysqld-iptables]
    
    enabled  = false
    filter   = mysqld-auth
    action   = iptables[name=mysql, port=3306, protocol=tcp]
               sendmail-whois[name=MySQL, dest=root, [email protected]]
    logpath  = /var/log/mysqld.log
    maxretry = 5
    
    
    # Jail for more extended banning of persistent abusers
    # !!! WARNING !!!
    #   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
    [recidive]
    
    enabled  = false
    filter   = recidive
    logpath  = /var/log/fail2ban.log
    action   = iptables-allports[name=recidive]
               sendmail-whois-lines[name=recidive, logpath=/var/log/fail2ban.log]
    bantime  = 604800  ; 1 week
    findtime = 86400   ; 1 day
    maxretry = 5
    
    # PF is a BSD based firewall
    [ssh-pf]
    
    enabled=false
    filter = sshd
    action = pf
    logpath  = /var/log/sshd.log
    maxretry=5
    
    • Greg Petersen
      Greg Petersen almost 11 years
      Could you please show us your jail configuration?
    • Ergec
      Ergec almost 11 years
      ok added conf file
    • Valentin Bajrami
      Valentin Bajrami almost 11 years
      @Ergec you have to modify the standard ssh port found in /etc/services You have there ssh 22/tcp Change the port that suits your needs.
    • Ergec
      Ergec almost 11 years
      @val0x00ff add you comment as answer because that was exactly what I need. I'll accept your answer. Seems fail2ban uses ports in /etc/services to create iptables rules. Thanks a lot.
    • Valentin Bajrami
      Valentin Bajrami almost 11 years
      @Ergec, No problem. Though specifying the port as 12345 in the action section.. would also work since you are hardcoding the port. port=ssh was ofcourse mapped to port 22.
    • Ergec
      Ergec almost 11 years
      Ok seems I have two correct answers from @quanta and val0x00ff and both solve my problem. But I'll pick val0x00ff because it seems like a more global fix. Correct me if I'm wrong.
  • Ergec
    Ergec almost 11 years
    This answer also fixed my problem. Thanks a lot @quanta up voted