How to Check if FTP Port 21 is Blocked

Some local ISPs are blocking the default TCP port for FTP connection – 21, which may cause connection issues. Below you may view how to check if that port is blocked in 3 operating systems:
 
  1. Windows OS:
    In order to check if port 21 is blocked, click on the “Start Menu”
    Search for “cmd” and press enter to go to "Command Prompt"
    In the newly opened command prompt enter the following command followed by “Enter” button:
    telnet YourDomain.com 21

  2. Linux OS:
    In order to check if port 21 is blocked, simply open your favorite shell/terminal and type the following command followed by “Enter” button:
    telnet YourDomain.com 21

  3. Apple/Mac OS:
    In order to check if port 21 is blocked, navigate to Mac HD -> “Applications” directory -> Utilities sub-directory. Once the terminal is opened type the following command followed by “Enter”:
    telnet YourDomain.com 21
If you receive the following result, that means that port 21 is not blocked from your ISP or your Firewall:
Connected to YourDomain.com.
Escape character is ‘^]’.
220———- Welcome to Pure-FTPd [privsep] [TLS] ———-
220-You are user number 1 of 50 allowed.
220-Local time is now 07:16. Server port: 21.
220-This is a private system – No anonymous login
220-IPv6 connections are also welcome on this server. 220 You will be disconnected after 15 minutes of inactivity.
If you receive the massage like this, that is mean port 21 is blocked by your local ISP or your Firewall:
telnet: connect to address IP_Address: Connection refused

Then you should review your firewall or contact your local ISP for further assistance.

Was this answer helpful?

 Print this Article

Also Read

Adding a New FTP Account

An FTP account creates a folder on the "public_html" level of your site that allows external...

Where should I upload the files for my addon domain?

When you create an addon domain, the webroot directory is created for it. Thus, you can visit...

Where should I upload the index.html file for my site?

The index.html file for your site should be uploaded to the /public_html directory. That’s how...

How do I use FTP?

FTP (File Transfer Protocol) is a method by which you can transfer files between computers,...

Failed to Retrieve Directory Listing

Response: 200 PORT command successful. Consider using PASV. Command: LIST Error: Connection...