/etc/init.d/iptables

iptables

#!/bin/bash
# see http://serverfault.com/a/363745/45819

start() {
   echo "Starting iptables." 

   EXT="eth0"
   TUNNELS="tun+"

   iptables -F
   iptables -X
   iptables -P INPUT DROP # set policy which is applied at the end.

   # note that outgoing connections are not affected in this script!

   # allow everything on loopback-device 
   iptables -A INPUT -i lo -p all -j ACCEPT

   # allow established connections
   iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT

   # open ssh and http
   iptables -A INPUT -p tcp -m tcp --dport 22 -j ACCEPT 
   iptables -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT 

   # Allow incoming pings
   iptables -A INPUT -p icmp --icmp-type echo-request -j ACCEPT

   # no more rules can be added to the INPUT chain after this: 
   iptables -A INPUT -j DROP


}

stop() {
   echo "Stopping iptables." 
   iptables -F
   iptables -X
   iptables -P INPUT ACCEPT
}

status() {
   iptables -L -vn
}

case "$1" in
   start)
      start
      ;;
   stop)
      stop
      ;;
   restart)
      stop
      start
      ;;
   status)
      status
      ;;
   *)
      echo "Usage: $0 start|stop|restart|status" 
      exit 1
   ;;
esac

exit 0