Example of IPTABLES Port ing in Centos

We now have two servers, one with an intranet IP address and the other with an intranet IP address. To access an intranet server, you need to map the intranet port to the Internet.

Server 1:

Internet IP address 10.0.0.1
Intranet IP address 255.0.0.1
Server 2:

Intranet IP address 255.0.0.2

Now we need to map server2's intranet port 22 to server1's Internet Port 30022.

First, clear the existing linked list.

$ Iptables-F
$ Iptables-X
$ Iptables-Z

Then we do Port ING.

$ Iptables-t nat PREROUTING-d 10.0.0.1-p tcp -- dport 30022-j DNAT -- to route 0.0.2: 22
$ Iptables-t nat POSTROUTING-d route 0.0.2-p tcp -- dport 22-j SNAT -- to route 0.0.1
$ Iptables save

Now we can remotely access server2 through Port 30022 of 10.0.0.1.