March 20, 2017
1 min read
Checking port 21 whether it is blocked or not, can be through the terminal or command prompt. Port 21 is generally made for FTP (File Transfer Protocol) connections, this port is used by FTP clients to connect to the FTP server when the user will access the FTP server. So if you have problem connecting FTP client to your FTP account, this is a great way to check if port 21 is blocked or not.
Read also: How to Check SMTP Port 587 is Not Blocked
What Do You Need to Check FTP Ports?
Before moving on to the next step, make sure that you can access the Command Prompt (Windows), Terminal (Linux), or MacOS Terminal.
Step 1: Open Command Prompt/Terminal on Your Computer
There are slight differences in this first step, depending on the operating system you are using. If you are using Windows, you can use the Command Prompt. Meanwhile, you can use Terminal for both Linux and MacOS operating systems. Here we present the method for you.
First of all, please press the button Windows + R on your keyboard to display functions Run. After that you will see a screen like below.
type cmd in the available fields, then press the button OK.
To check if port 21 is open, telnet on Windows needs to be enabled first. If telnet is not active, you will get a message like below.
style="padding-left: 30px;">'telnet' is not recognized as an internal or external command, operable program or batch file.
If you see a message like the one above, please enable telnet first. You can follow the steps below.
1. Click button Start on Windows or press the key Windows on your keyboard.
2. Type “Turn Windows features on and off“then press ENTER.
3. After that, search Telnet Client, put a check mark, then press the button OKas seen in the image below.
To open Terminal on Linux, please press button Ctrl+alt+T simultaneously. Next you will see a black screen console as shown below.
Also Read: Easy Ways to Create an FTP Server
Meanwhile, to open Terminal on MacOS, please first open the MacOS Launchpad by pressing the button F4.
After that please search by typing “terminal” without quotes and press ENTER.
Step 2: Use Telnet to Check Port 21 Not Blocked
After the Command Prompt / Terminal console opens, please type the code below. Enter your website’s domain name instead yourdomain.com.
telnet domainanda.com 21
If it is successful, you will see a message as seen below.
220---------- Welcome to Pure-FTPd [privsep] [TLS] ---------- 220-You are user number 8 of 100 allowed. 220-Local time is now 09:57. 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 3 minutes of inactivity.
If you don’t see the message, it means Port 21 is blocked.
In this tutorial you have learned how to use telnet to check if the default FTP port 21 is open. If the results of the check show that the port is closed, the best thing you can do is to contact your service provider and request that this port be opened. Closing Port 21 means you cannot use FTP hosts on the network.
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