linux 端口映射设置

### 端口转发
iptables -t nat -A PREROUTING -p tcp --dport 新端口 -j REDIRECT --to-ports 旧端口

### 服务器中转
firewall-cmd --add-forward-port=port=1433:proto=tcp:toaddr=113.88.12.56:toport=1433
firewall-cmd --reload
firewall-cmd --list-all