fail2ban/config/action.d/iptables-multiport-log.conf

# Fail2Ban configuration file
#
# Author: Guido Bozzetto
# Modified: Cyril Jaquier
#
# make "fail2ban-<name>" chain to match drop IP
# make "fail2ban-<name>-log" chain to log and drop
# insert a jump to fail2ban-<name> from -I <chain> if proto/port match
#
#

[INCLUDES]

before = iptables-blocktype.conf

[Definition]

# Option:  actionstart
# Notes.:  command executed once at the start of Fail2Ban.
# Values:  CMD
#
actionstart = iptables -N fail2ban-<name>
              iptables -A fail2ban-<name> -j RETURN
              iptables -I <chain> 1 -p <protocol> -m multiport --dports <port> -j fail2ban-<name>
              iptables -N fail2ban-<name>-log
              iptables -I fail2ban-<name>-log -j LOG --log-prefix "$(expr fail2ban-<name> : '\(.\{1,23\}\)'):DROP " --log-level warning -m limit --limit 6/m --limit-burst 2
              iptables -A fail2ban-<name>-log -j <blocktype>

# Option:  actionstop
# Notes.:  command executed once at the end of Fail2Ban
# Values:  CMD
#
actionstop = iptables -D <chain> -p <protocol> -m multiport --dports <port> -j fail2ban-<name>
             iptables -F fail2ban-<name>
             iptables -F fail2ban-<name>-log
             iptables -X fail2ban-<name>
             iptables -X fail2ban-<name>-log

# Option:  actioncheck
# Notes.:  command executed once before each actionban command
# Values:  CMD
#
actioncheck = iptables -n -L fail2ban-<name>-log >/dev/null

# Option:  actionban
# Notes.:  command executed when banning an IP. Take care that the
#          command is executed with Fail2Ban user rights.
# Tags:    See jail.conf(5) man page
# Values:  CMD
#
actionban = iptables -I fail2ban-<name> 1 -s <ip> -j fail2ban-<name>-log

# Option:  actionunban
# Notes.:  command executed when unbanning an IP. Take care that the
#          command is executed with Fail2Ban user rights.
# Tags:    See jail.conf(5) man page
# Values:  CMD
#
actionunban = iptables -D fail2ban-<name> -s <ip> -j fail2ban-<name>-log

[Init]

# Default name of the chain
#
name = default

# Option:  port
# Notes.:  specifies port to monitor
# Values:  [ NUM | STRING ]  Default:
#
port = ssh

# Option:  protocol
# Notes.:  internally used by config reader for interpolations.
# Values:  [ tcp | udp | icmp | all ] Default: tcp
#
protocol = tcp

# Option:  chain
# Notes    specifies the iptables chain to which the fail2ban rules should be
#          added
# Values:  STRING  Default: INPUT
chain = INPUT