How to check if FTP port 21 is not blocked

If you’re experiencing problems with your FTP connection, it’s worth investigating if port 21 is causing the connection failure. In this guide, we will show you how to check if your FTP port 21 is open.

How to Check if Port 21 is Open?

Before we begin, please ensure you have access to your system’s console. You can find more information on how to access the system console on Windows, Linux, and macOS here.

Here’s how to check for a block on FTP port 21:

1. Open the system console and enter the following command, replacing <yourdomain.com> accordingly. This command works for all operating systems: telnet yourdomain.com 21

2. If the port is not blocked, you will receive a response like “220 FTP server ready.” Please note that this message may vary.
3. If the 220 response does not appear, it indicates that the port is blocked. In such cases, we recommend contacting your system administrator to open the port.

Enabling the Telnet Client

Since we use the telnet command to verify the connection, ensure that your operating system has the telnet-client installed.

Telnet is a client-server protocol that allows remote control of computers and, in this case, helps test FTP port 21 connectivity. Here’s how to enable the Telnet client on Windows:

1. Press the Windows+R keys together, then enter control to open your Control Panel.
2. Navigate to Programs -> Programs and Features. In the left panel, select Turn Windows features on or off.
3. In the new dialog, check the Telnet Client box and click OK.

What is FTP Port 21?

FTP is an Internet protocol that facilitates bulk file exchange within a network. For proper functioning, FTP uses two ports: port 21 for command and control, and port 20 for data transport. An FTP client cannot operate if it cannot connect to these FTP ports.

However, some routers and firewalls block port 21 due to security concerns as hackers often target FTP servers through this port. If you’re experiencing FTP connection problems, it’s crucial to check for any blocks on port 21.

Conclusion

Routers and firewalls may block FTP port 21 for security reasons, so it’s essential to verify the port connection before attempting File Transfer Protocol operations. For more information about FTP, refer to additional resources.

We hope this tutorial has been helpful. If you have any further questions, feel free to leave a comment below.