To Forward all Traffic from one machine to another IPTABLES

Following Rules are Required to Forward all Traffic From __YOURMACHINE__ to __NEWGATEWAY__
    /sbin/iptables -t filter -I FORWARD -s __YOURMACHINE__ -i eth0 -p tcp -j ACCEPT
    /sbin/iptables -t nat -I PREROUTING -s __YOURMACHINE__ -i eth0 -p tcp -j ACCEPT
    /sbin/iptables -t mangle -I PREROUTING -s __YOURMACHINE__ -i eth0 -j ROUTE --oif eth0 --gw __NEWGATEWAY__