Ubuntu 网关服务器配置

1.设置Linux内核支持ip数据包的转发

　 echo "1" > /proc/sys/net/ipv4/ip_forward

  or 

      vi /etc/sysctl.conf   net.ipv4.ip_forward=1

2.配置双IP

auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address 192.168.6.xx
netmask 255.255.255.0
gateway 192.168.6.1
dns-nameservers 8.8.8.8

auto eth0:0
iface eth0:0 inet static
  address 10.2.0.1
  netmask 255.255.255.0

3.添加IP伪装规则

iptables -t nat -A POSTROUTING -S 192.168.1.0/24 -O eth1 -j MASQUERADE