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Reprinted from the article of Intranet Penetration Tool: Use Serv-U to build an FTP server and access it from the public network [Intranet Penetration]
1 Introduction
With the development of science and technology today, mobile electronic devices seem to be the protagonists of our lives, and smartphones and tablets are almost never without us. However, smart phones and tablet computers also have shortcomings, that is, their own storage capacity is too small, and a large-capacity storage device that can retrieve data at any time is very necessary. Today, the author will introduce to you how to use Serv-U+Cpolar intranet penetration on the computer to build an ftp protocol server, so that we can read and retrieve documents at any time.
2. Local FTP construction
As an integral part of the TCP/IP protocol, the FTP protocol is mainly used to transmit webpage data and files to the Web server; at the same time, due to the high transmission efficiency of FTP, it is often used to transmit large electronic data. Usually the FTP protocol has two components, one is the FTP server (for data storage), and the other is the FTP client (to access the specified server). The Serv-U introduced today allows us to easily build a FTP server.
2.1 Serv-U download and installation
Serv-U is very powerful, stable and easy to set up, so it is very popular among users. If you want to build your own Serv-U server, you must first download Serv-U from the Serv-U official website ( http://www.serv-u.com.cn/ ).
The computer used by the author has Windows operating system installed, so choose the Windows version to download. As for other operating systems, you can choose according to your needs.
After the download is complete, decompress the downloaded compressed package, and double-click the decompressed .exefile to install it
After entering the installation program, just click all the way 下一步, and the installation will be completed in no time. When Serv-U is run for the first time after the installation is complete, it will display "Currently defined domain, do you want to define a new domain first", select it directly 是.
After entering 自定义域the setting page, the list on the left is the content we need to set. If there is no special requirement, just enter a few simple content, and then click to 下一步complete the setting.
First of all, Serv-U will ask us to set up the custom domain 名称, just fill in the name we like here
In the third step, Serv-U will ask us to fill in domain URL（域名网址）, here we can fill in the local address according to its example ( 127.0.0.1); the second line is file sharing repository（共享文件存储库）, the author chooses to share the entire E disk. If you need to set it as a shared folder, you can click the "folder" icon on the right side of the column to select
The fourth step is to set the output port of Serv-U. Similarly, if there is no special requirement, or the default port 80 of the system is not occupied, you do not need to modify the settings. But port 80 of the author's Windows system has been occupied, so port 80 needs to be modified, in this example to 83.
It should be noted that the port number modified in this step needs to be remembered, so that we can conduct FTP transfer web page access tests later, and this port number will also be used when Cpolar performs intranet penetration.
There is no need to modify the content in the next fifth step, just 下一步go directly.
The sixth step (the last step) is about replying to the password. If necessary, the judge can set it by himself.
After completing the above steps, we have completed the shared area setting of Serv-U, and the next step is the next 添加域用户step. Here we just need to follow the software prompts to operate. It should be noted that in the last step of the domain user setting, it will involve the user's permission to access shared files. If you do not want the user to modify the shared file, you must select "Read-only access", otherwise select "Full access".
After setting the access user, you can click 完成to keep the settings of the access user.
After completing the above settings, we can try to access the shared web page of Serv-U on the local computer.
2.2 Serv-U shared web page test
Since the Serv-U address we set before is a local address (127.0.0.1), here we need to enter the IP address of the local computer plus the port number in the browser, and the specific format is http://192.168.X.X:之前设置的端口号. In this example, the Serv-U access address is (http://192.168.157.1:83).
As long as the entered address is correct and there is no problem with the previous Serv-U software settings, the Serv-U login interface will be displayed, which means that the FTP server we built using Serv-U is successfully online and can accept visitor access. But at this time, the Serv-U webpage can only be accessed within the scope of the LAN. To make this webpage accessible anywhere, we need to use Cpolar to create an intranet penetration data tunnel.
2.3 Download and install Cpolar
After the local Serv-U server is set up, we can install Cpolar intranet penetration to prepare for our FTP server to go online. Like Serv-U, we can directly visit Cpolar official website ( https://www.cpolar.com/ ) and choose the version suitable for our computer operating system to download.
The author uses the Windows operating system, so choose the Windows version to download.
After the download of Cpolar is complete, decompress the downloaded file, double-click the decompressed .msifile, and the installation program can be executed automatically. Then just go all the way Nextto complete the installation.
Since cpolar will create an independent data tunnel for each user, supplemented by user passwords and token codes to ensure data security, we need to register users before using cpolar. The registration process is also very simple. Just click on the upper right corner of the cpolar homepage 用户注册and fill in the necessary information on the registration page to complete the registration.
3. Local FTP publishing
After completing the deployment of the local Serv-U server and the installation and registration of Cpolar intranet penetration, we can start to create a public Internet address for the Serv-U shared webpage, that is, the intranet penetration data tunnel, so that we can Next, you can also access the FTP server at home.
Since the author does not want to set the webpage address of Serv-U every day (cpolar will reset the data tunnel address of free users every 24 hours), so I upgrade cpolar to VIP level to obtain the long-term stable data tunnel privilege.
3.1 Cpolar cloud settings
To achieve the purpose of intranet penetration, you need to log in to cpolar's official website first, find the 预留button on the left side of the user's main page, and click to enter the reserved page of cpolar's data tunnel. A public Internet address is generated here (it can also be regarded as the entrance of the data tunnel). Since this address is not connected to the local software output port at this time, it can also be regarded as a blank data tunnel.
On the reservation page, you can see many kinds of data tunnels that can be reserved. Here we select 保留二级子域名the field.
In the field of "Reserve the second-level subdomain name", you need to set several simple information,
地区: The area where the server is located, just select the nearest one二级域名: Will eventually appear in the generated public Internet address as one of the identifiers of the network address描述: It can be regarded as the description of this data tunnel, which can be distinguished from other tunnels)
After completing these settings, you can click 保留the button on the right to keep this data tunnel.
Of course, if this data tunnel is no longer intended to be used, you can also click on the right xto delete it easily, saving valuable tunnel quota.
3.2 Cpolar Local Settings
After completing the setting of the cpolar cloud and keeping the blank data tunnel, we return to the local cpolar client and connect the blank data tunnel generated in the cloud with the local Serv-U web page port to officially open the Serv-U intranet penetration data tunnel. Same as logging in to the Cpolar cloud, we open and log in the cpolar client locally (you can enter it in the browser to localhost:9200access it directly, or click the shortcut of the cpolar client in the start menu)
隧道管理Click the button on the left side of the main interface of the client 创建隧道to enter the local tunnel creation page (if you want to create a temporary data tunnel without a 24-hour reset address, you can directly set it here instead of setting a blank data tunnel on the cpolar official website).
On this page, several information settings also need to be made, including:
1.
隧道名称– It can be regarded as cpolar’s local tunnel information comment, as long as it is convenient for us to distinguish;
2.协议– Since Serv-U outputs a web page, the http protocol is selected here;
3.本地地址– The local address is the Serv-U website
4. – Since we have reserved the data域名类型二级子域名Sub Domaintunnel of the second-level subdomain name in the cpolar cloud and generated the public Internet second-level domain name of the Serv-U web page, Therefore, we check this line (if the reserved domain name is custom domain name, check the custom domain name), and fill in the reserved second-level subdomain name in the next column, which is "servuFTP" in this example. Of course, if you are creating a temporary data tunnel, just check "Random Domain Name" directly, and the cpolar client will generate a network address by itself, without having to set it in the cpolar cloud; 5. – This line is the same as the setting in the cpolar cloud
,地区both It is the choice of the server region, we can fill it in according to the actual use;
After completing the information required to create a tunnel on the cpolar client, you can click 创建the button at the bottom of the page to formally generate a data tunnel that can be accessed from the public Internet to the local Serv-U web page.
After the data tunnel is created, the cpolar client will automatically jump to 隧道管理the -- 隧道列表page. On this page, we can see the status of the newly created Serv-U data tunnel, and we can also perform operations on this data tunnel here, such as starting, suspending, and deleting; To modify, you can also click the "Edit" button here to enter the data tunnel information modification page.
4. Public network access test
状态Finally, we click the button on the left side of the cpolar client 在线隧道列表to enter the online tunnel list page, where we can see the public Internet address of the Serv-U web page.
Through this address, we can access the Serv-U webpage located on the local computer on other computers (or devices), and retrieve and access shared files.
5 Conclusion
It can be seen that the steps and process of using Cpolar to publish Serv-U webpages are not complicated, and cpolar, as an intranet penetration software, can not only publish Serv-U webpages, as long as the port number of the webpage (or software) to be published Enter cpolar to create a data tunnel between the public Internet and the local webpage (software).