iptables -t nat -A POSTROUTING -s 10.8.0.0/24 -o eth0 -j MASQUERADE
service iptables save
service iptables restart

iptables -L

Chain INPUT (policy ACCEPT)
target    prot opt source        destination

Chain FORWARD (policy ACCEPT)
target    prot opt source        destination

Chain OUTPUT (policy ACCEPT)
target    prot opt source        destination

iptables --table nat --list

iptables -t nat -L

iptables -vL -t filter
iptables -vL -t nat
iptables -vL -t mangle
iptables -vL -t raw
iptables -vL -t security

# iptables-save > iptables_bckp
# vim iptables_bckp
# iptables-restore < iptables_bckp

iptables -t nat -L

#!/bin/bash

 echo "Filter table:"
 iptables -t filter -L

 echo "Nat table:"
 iptables -t nat -L

 echo "Mangle table:"
 iptables -t mangle -S

 echo "Raw table:"
 iptables -t raw -S

 echo "Security table:"
 iptables -t security

 echo
 echo "All rules in all tables printed"

# lsmod | grep ip_tables
ip_tables              13193  4 iptable_raw,iptable_mangle,iptable_nat,iptable_filter