How to check if port 21 is blocked?

Port 21 is the default port for using with your FTP. However, in some cases the ISP (Internet Service Provider) might have this port blocked. Here are some easy ways to check if it is blocked on their side:

1. On Windows OS

• go to the Start Menu on the bottom left corner;
• click Run and type cmd;
• a small black window will open (command prompt);
• type telnet.mydomain.com 21

2. On MAC OS

• go to Applications directory;
• choose Utilities and this will open you a command line;
• type telnet.mydomain.com 21

3. On Linux

• open your terminal emulator;
• type telnet.mydomain.com 21

If the test goes through correctly, you should get a welcome message. It should look something like this:

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 don’t get such a message, then most probably your ISP has blocked port 21 and you should contact them for further assistance.