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项目组同事需要将SQL请求转发到另一台服务器上，于是通过iptables实现此功能
[root@gea-1 ~]# echo 1 > proc/sys/net/ipv4/ip_forward [root@gea-1 ~]# iptables -t nat -A PREROUTING -d 192.168.18.19 -p tcp --dport 1521 -j DNAT --to 192.168.4.74:1521 [root@gea-1 ~]# iptables -t nat -A POSTROUTING -d 192.168.4.74 -p tcp --dport 1521 -j SNAT --to 192.168.18.19
查看nat 规则：
[root@gea-1 ~]# iptables -L -n -t nat Chain PREROUTING (policy ACCEPT) target prot opt source destination DNAT tcp -- 0.0.0.0/0 192.168.18.19 tcp dpt:1521 to:192.168.4.74:1521 Chain POSTROUTING (policy ACCEPT) target prot opt source destination SNAT tcp -- 0.0.0.0/0 192.168.4.74 tcp dpt:1521 to:192.168.18.19 Chain OUTPUT (policy ACCEPT) target prot opt source destination
Telnet测试：
[root@gea-1 ~]# telnet 192.168.4.74 1521 Trying 192.168.4.74... Connected to localhost (192.168.4.74). Escape character is ‘^]‘.
保存iptables设置：
[root@gea-1 ~]# iptables-save >> /etc/sysconfig/iptables
原文：http://www.cnblogs.com/lichmama/p/4115556.html