How to check if FTP port 21 is blocked

Knowledgebase Article

How to check if FTP port 21 is blocked

Sometimes you may find that port 21 has been blocked by your ISP, or by your company's firewall. This will prevent you connecting to the FTP server to upload and download your files.

You can check if this is the cause of your connectivity problems in the following way:

Windows

Press Start > Run

This will bring up a small window. In that window, type cmd. This will bring up a black window, which is called the DOS Prompt. Enter the following and press enter:

telnet mydomain.com 21

Replace mydomain.com with your own domain name.

Apple Mac

In your Mac Applications directory, you will find a sub folder called Utilities. This will contain an application called Terminal. Open this application. Enter the following and press enter:

telnet mydomain.com 21

Replace mydomain.com with your own domain name.

The Results

If the connection has been successful, you should see the following:

220---------- Welcome to Pure-FTPd [TLS] ----------
220-You are user number 5 of 50 allowed.
220-<<
220-#########################################################
220-Please upload your web files to the public_html directory.
220-Note that letters are case sensitive.
220-#########################################################
220->>
220-Local time is now 03:35. 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 see anything other than this then your connection has not been successful and you should contact your ISP, or potentially, if you are in an office, your network administrator, to ask them to unblock port 21.

If you still have any further problems don't hesitate to contact our support and we will be happy to help!