It is best practice to restrict FTP access to a IP. The only requirement is that you should have dedicate IP on your internet hosting subscription. You can use what is my IP in google search to know your internet host IP. If this is not a fully qualified IP or changes every time you restart your router. Then most likely it is not a dedicate IP.
Following are the steps to restrict FTP in IIS
- Open Internet Information Services (IIS) Manager
- Deny all access
- Add IP ALLOW address
1. Open Internet Information Services (IIS) Manager.
2. Under Sites click on your FTP sites. The following panel will appear.
3. Double click FTP IPv4 Address and Domain Restrictions or FTP IP Address and Domain Restrictions and click Edit Feature Settings in action pane and select option as shown in following image.
This will deny access to all connection. So your FTP should not connect.
4. Now we need to allow our Dedicate IP address. Click on Add Allow Entry in action pane and in Specific IP Address field, enter your desired IP address to allow access to your FTP accounts and click OK.
The allow entry will appear as below.
You should be able to connect to FTP for the IP as specified. Try connecting from other internet IP.
Enjoy
