snat.txt

snat.txt

#!/bin/sh

INET_IF="ppp0"

LAN_IF="eth1"

LAN_IP_RANGE="192.168.0.0/24"

IPT="/sbin/iptables"

MODPROBE="/sbin/modprobe"

echo "1" > /proc/sys/net/ipv4/ip_forward

/sbin/depmod -a

$MODPROBE ip_tables

$MODPROBE ip_conntrack

$MODPROBE ip_conntrack_ftp

$MODPROBE iptable_nat

$MODPROBE ip_nat_ftp

$MODPROBE ipt_LOG

for TABLE in filter nat mangle ; do

$IPT -t $TABLE -F

$IPT -t $TABLE -X

done

$IPT -P INPUT ACCEPT

$IPT -P OUTPUT ACCEPT

$IPT -P FORWARD ACCEPT

$IPT -t nat -P PREROUTING ACCEPT

$IPT -t nat -P OUTPUT ACCEPT

$IPT -t nat -P POSTROUTING ACCEPT

$IPT -A FORWARD -i $INET_IF -o $LAN_IF -m state --state ESTABLISHED,RELATED -j ACCEPT

$IPT -A FORWARD -i $LAN_IF -o $INET_IF -j ACCEPT

$IPT -t nat -A POSTROUTING -s $LAN_IP_RANGE -o $INET_IF -j MASQUERADE