서버1 : 사설아이피(172.16.13.1/16)서버2 : 사설아이피(172.16.12.1/16) + 공인아이피 (115.68.210.XXX)
서버2 설정
# iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
# echo 1 > /proc/sys/net/ipv4/ip_forward
서버1 설정
# vim /etc/network/interface
auto eth0
iface eth0 inet static
address 172.16.13.1
netmask 255.255.0.0
gateway 172.16.12.1
