[network] nat

* how to nat, masquerade with iptables
wan: eth0, lan: eth1
iptables --table nat --append POSTROUTING --out-interface eth0 -j MASQUERADE
iptables --append FORWARD --in-interface eth1 -j ACCEPT
echo 1 > /proc/sys/net/ipv4/ip_forward

cf) flush iptables

iptables --flush

iptables --table nat --flush

iptables --delete-chain

iptables --table nat --delete-chain

* iptables concept

ref: http://www.howtoforge.com/nat_iptables