#!/bin/sh
#flush script, which deletes all active rules
#and chains, and resets default policies to "accept"
#this is just like having no firewall at all

#define variables
ipt="/sbin/iptables"

echo "The firewall is now being shut down. All policies are set to ACCEPT, all rules and chains are deleted, all counters are set to zero."

#Set default policies to ACCEPT everything
$ipt -P INPUT ACCEPT
$ipt -P FORWARD ACCEPT
$ipt -P OUTPUT ACCEPT
$ipt -t nat -P OUTPUT ACCEPT
$ipt -t nat -P PREROUTING ACCEPT
$ipt -t nat -P POSTROUTING ACCEPT
$ipt -t mangle -P PREROUTING ACCEPT
$ipt -t mangle -P POSTROUTING ACCEPT

#Zero out all counters 
$ipt -Z
$ipt -t nat -Z
$ipt -t mangle -Z

# Flush all active rules, delete all chains
$ipt -F
$ipt -X 
$ipt -t nat -F
$ipt -t nat -X
$ipt -t mangle -F
$ipt -t mangle -X