Access the Intranet FTP server through port ing

I once saw an article on the Internet that introduced a method for direct access to the Intranet. In fact, we only need to use the port ing tool to easily penetrate the Intranet. Port er is a tool like this. It is even more worth mentioning that it breaks away from the command line mode and provides a graphic interface operating environment.

I. Basic Ideas

To help you better understand the principle, let me talk about it first. Assume that there is A local area network (LAN) with host A. In addition to host B, the local area network (LAN) also has host B. Of course, host B accesses the Internet through host. In addition, A machine that can access the Internet is C, which is not in the same LAN as A and B. Generally, machine C can only access host A, but cannot penetrate the LAN and access host B. After port ing, when host C accesses the specified port of host A, the "port Er" on host A takes effect, it transfers the data on the specified port to the specified port of another machine in the LAN, so as to access the Intranet machine. In this case, everyone understands it!

Ii. Operation Process

Next, I will take FTP on a machine numbered 46 in the LAN as an example to illustrate the specific operation process of port ing. Of course, the ftp on machine 46 must be installed in advance.

Step 1: Download "port Er" on the host and click "add" in the toolbar. The "Add/modify port ing" setting interface is displayed.

Step 2: Select "Any IP" in "Enter IP", and enter the port you want to use in "enter port". Here I enter 4843. Enter the IP address of the Intranet machine in "output IP". Here is "10.51.5.46", and "output port" is the default port 21 of Intranet FTP. At the same time, select the "automatically start when the program is running" option in the upper right corner. After everything is set, click "OK" (1 ).

 

 

Figure 1

 

Step 3: After the above settings, a ing project named "machine 46" will appear on the main interface. Then, you only need to start it to access the Intranet. Select it and click "start" in the toolbar. Then, switch to the "log record" column to see the effect (2 ).

 

 

Figure 2

 

NOTE: For the sake of security, we recommend that you check the content in "link monitoring" frequently so that you can know the IP address of the link in time.

Step 4: now we can notify our friends to access the Intranet FTP. Assume that the Internet address of the host is 218. x. x.1, then you just need to let your friend access address: ftp://218.x.x. 1: 4843/, you can directly access the FTP on the Intranet machine numbered 46.

Iii. Advantages and Disadvantages

The advantage of direct access to the Intranet is obvious. If nothing else, at least FTP resources are fully utilized. However, you must be reminded that direct access to the Intranet may threaten the security of the Intranet. I believe that most of my friends pay attention to host security, but they often ignore the security settings of Intranet machines. Once you implement direct access to the Intranet, you must treat Intranet machines like hosts, otherwise your entire network may be in danger.