FTP file server configuration has two active mode and passive mode, here is mainly passive mode configuration
1. FileZilla Server configuration
1. Set the passive mode port transmission range. Generally, the FTP passive mode transmission port is between 1024-65535. Filezilla does not make additional restrictions. The interval within this range can be set
2. Set to use the designated IP, and fill in the server's external network IP, as shown in the red circle as shown below.
3. Be sure to open the server's corresponding TCP port channel. Set 50101-50200 as shown in the figure below. Make sure that the firewall does not close the designated port and the server's external network does not block the designated port. Cloud servers such as Alibaba Cloud, etc., must be placed in the configuration security group Open ports within the specified range! (As shown in the figure below, to set the passive mode port, you must release the 50101-50200 TCP port in the security group. It is best to keep the active mode port open. If the default communication port is 21, the transmission port is 20. It is recommended to keep 21 And 20 ports unblocked)
4. The port range opened in passive mode may affect the number of simultaneous FTP download connections. It is recommended to increase the port range for servers that are upgraded by a large number of terminal devices. The passive mode communication port does not have to be designated as 21. Theoretically, it can be any unoccupied port of other servers, but it should be noted that this port cannot overlap with the FTP passive mode data transmission port. (Under the window, you can enter netstat -ano through cmd to query the port occupied by the current system. 
2. IIS FTP server installation and configuration
Install IIS FTP server on Windows server
1. Add a role Web server (IIS) in the server manager
2. Pay attention to check FTP service during installation
Configure FTP service
1. Open the IIS Manager
2. Configure the application pool, it is recommended to be .NETFramework v4.0 or higher, and start after the configuration is completed (it is recommended to close or delete the original default application pool)
3. Create a new FTP page, right-click the "Website" directory, and then click Add FTP Site
4. Set the site name and path
5. Configure the IP and port, and close the SSL configuration without SSL willingness
Note: The specific parameter configuration can be changed in the FTP server console after the setting is completed
FTP server console settings
1. Bind the FTP port
2. Set FTP access path and application pool
3. Configure identity authentication
Ensure that basic authentication is enabled, anonymous can be turned off
4. Add specified user permission rules, specify the users and permissions allowed to access
The IIS FTP user is essentially the Windows Server system user. So before the establishment, you need to create other users under the current windows Server for FTP access (Of course, the default Administrator is also OK, but it is not recommended)
By default, Windows server requires users to have higher password strength. If for some reason, you cannot use a strong password, you can modify the password rules.
Open the local security policy and disable the'password must meet complexity requirements'
6. Configure FTP passive mode port range limit
It is recommended that the FTP passive mode port range of IIS is between 50000-65535, as shown in the figure below, set to 50000-50100, and the external IP address should also be set. The figure below is the external IP address. With filezilla Like, IIS also specify the need to maintain the smooth flow of network ports, and not being used by another program.
After the configuration is complete, start the service
After the configuration is complete, it is best to use the FTP client to check if there is a problem with the download. It is recommended to use the filezilla client
Use normal FTP, set the transfer to passive to test whether the passive mode is available
Note: If the communication port configured by IIS is not the default 21, you need to consider whether the server will return the local IP address. Most FTP client software has the function of setting the local IP to be replaced by the server IP, and the download can be completed after selection
Analysis of the problem of unable to establish FTP connection after configuration
1. First judge whether the machine can access the FTP service, open the browser in the configured FTP server, enter ftp://ip:port and press Enter to see if the window in the figure below can be opened (ip, port refer to actual Set IP and port)
2. If it can be opened and successfully logged in, but the external network cannot be connected, it is recommended to consider the connection between the port and the external network, which is generally a firewall or cloud server security group.
3. If you can't open it in this way, it is recommended to carefully check whether there is any configuration error or missing in the previous operation. In addition, it is also possible that the IP domain name has been redirected. Consider replacing the IP with 127.0.0.1 or localhosts and try again.