IPT=/sbin/iptables
$IPT -F $IPT -t nat -F
$IPT -P INPUT DROP
$IPT -P OUTPUT DROP
$IPT -P FORWARD DROP
$IPT -t filter -A INPUT -i lo -j ACCEPT $IPT -t filter -A OUTPUT -o lo -j ACCEPT
$IPT -t filter -A INPUT -m state –state RELATED,ESTABLISHED -j ACCEPT $IPT -t filter -A OUTPUT -m state –state RELATED,ESTABLISHED -j ACCEPT $IPT -t filter -A FORWARD -m state –state RELATED,ESTABLISHED -j ACCEPT
$IPT -t filter -A INPUT -p tcp –dport 22 -j ACCEPT $IPT -t filter -A OUTPUT -p tcp –sport 22 -j ACCEPT
$IPT -t filter -A FORWARD -s 10.10.10.0/23 -j ACCEPT $IPT -t nat -A POSTROUTING -s 10.10.10.0/24 -j MASQUERADE