iptables Configuring server Port Forwarding

Environment:

centos6.5,192.168.1.10, external network bidirectional communication, binding domain name zlzkj.org;

winserver2008,192.168.1.11, the outside network can not directly access to the machine, but FTP, Remote Desktop, MySQL want to open to zlzkj.org access;

Goal:

ftp:192.168.1.10 21 forwards to 192.168.1.11 21;

Remote Desktop: 192.168.1.10 3389 forwards to 192.168.1.11 3389;

mysql:192.168.1.10 3361 forwards to 192.168.1.11 3361;

1. Need to turn on the data forwarding function of Linux first

Vim/etc/sysctl.conf

Change Net.ipv4.ip_forward=0 to 1

Sysctl-p

2. Change Iptables, run the following command

#将192.168.1.10 21 Port data is forwarded to 192.168.1.11:21.

Iptables-t nat-a prerouting-d 192.168.1.10-p tcp–dport 21-j dnat–to-destination 192.168.1.11:21

#将192.168.1.11 21 Port data is returned with the source IP changed to 192.168.1.10

Iptables-t nat-a postrouting-d 192.168.1.11-p tcp–dport 21-j snat–to-source 192.168.1.10

#远程桌面

Iptables-t nat-a prerouting-d 192.168.1.10-p tcp–dport 3389-j dnat–to-destination 192.168.1.11:3389

Iptables-t nat-a postrouting-d 192.168.1.11-p tcp–dport 3389-j snat–to-source 192.168.1.10

#MySQL

Iptables-t nat-a prerouting-d 192.168.1.10-p tcp–dport 3361-j dnat–to-destination 192.168.1.11:3361

Iptables-t nat-a postrouting-d 192.168.1.11-p tcp–dport 3361-j snat–to-source 192.168.1.10

3. Save Iptables

Service Iptables Save

iptables Configuring server Port Forwarding