Configure server port forwarding using iptables

Configure server port forwarding using iptables

Environment:

CentOS6.5, 192.168.1.10, two-way Internet communication, binding domain name zlzkj.org;

WinServer2008, 192.168.1.11, cannot be accessed directly from the Internet, but ftp, remote desktop, and MySQL should be accessed on zlzkj.org;

Objectives:

Ftp: 21 of 192.168.1.10 is forwarded to 21 of 192.168.1.11;

Remote Desktop: 3389 of 192.168.1.10 is forwarded to 3389 of 192.168.1.11;

MySQL: 3361 of 192.168.1.10 is forwarded to 3361 of 192.168.1.11;

1. You must first enable the data forwarding function for linux.

Vim/etc/sysctl. conf

Change net. ipv4.ip _ forward = 0 to 1.

Sysctl-p

2. Change iptables and run the following command:

# Forward data from port 21 of 192.168.1.10 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

# Change the source IP address to 192.168.1.10 when port 21 of 192.168.1.11 is returned

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

# Remote Desktop

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

-------------------------------------- Split line --------------------------------------

Disable the default firewall in CentOS 7.0 and enable the iptables firewall.

Iptables examples

Linux Firewall iptables

Basic use of iptables backup, recovery, and firewall scripts

Detailed description of firewall iptables usage rules in Linux

-------------------------------------- Split line --------------------------------------

This article permanently updates the link address: