vim /etc/sysctl.conf 这里是重点 配置路由转发，路由开启等都要用到。
# Controls IP packet forwarding
net.ipv4.ip_forward = 0
修改为
# Controls IP packet forwarding
net.ipv4.ip_forward = 1 允许内置路由
sysctl -p 更新
*nat
:PREROUTING ACCEPT [4174:254308]
:POSTROUTING ACCEPT [0:0]
:OUTPUT ACCEPT [2811:167684]
-A PREROUTING -i eth2 -p tcp -m tcp --dport 8002 -j DNAT --to-destination 192.168.195.28:8080
-A POSTROUTING -j MASQUERADE
COMMIT
