-bash: telnet: command not found

ELiv 2025

2 min read 06-03-2025

The error message "-bash: telnet: command not found" is a common one encountered on Linux and macOS systems. It simply means that the system cannot find the telnet command. This is usually because the telnet client isn't installed. Telnet is an older, insecure protocol, and many modern distributions don't include it by default for security reasons. This article will guide you through troubleshooting and resolving this issue.

Understanding the Telnet Command and its Security Risks

Telnet is a network protocol used for establishing a connection to a remote host. While it was once widely used, it transmits data in plain text, making it highly vulnerable to eavesdropping and man-in-the-middle attacks. For this reason, its use is strongly discouraged in favor of more secure alternatives like SSH (Secure Shell).

Why You Might Need Telnet (and Safer Alternatives)

While we strongly advise against using telnet due to security concerns, there might be very specific legacy situations where you need to connect to an older system that only supports telnet. However, even in these cases, exploring alternative and secure solutions should be a priority.

If you require remote access, consider these secure alternatives:

SSH (Secure Shell): This is the recommended replacement for telnet. It encrypts all communication, protecting your data from interception. Most Linux distributions include SSH by default.
PuTTY (for Windows): A popular SSH and telnet client for Windows systems.

How to Install Telnet

If, despite the security risks, you absolutely must use telnet, you'll need to install the telnet client package. The exact method varies depending on your operating system and package manager.

Installing Telnet on Debian/Ubuntu (apt):

Open your terminal and use the following command:

sudo apt update
sudo apt install telnet

Installing Telnet on Fedora/CentOS/RHEL (dnf/yum):

Open your terminal and use the following command:

sudo dnf install telnet  # Or sudo yum install telnet for older versions

Installing Telnet on macOS (Homebrew):

If you use Homebrew, install with:

brew install telnet

If you don't have Homebrew, you may need to use a different package manager or consult Apple's documentation. Again, we strongly advise against using Telnet due to security vulnerabilities.

Installing Telnet on other systems

For other distributions, consult your distribution's documentation for instructions on how to install software packages. Search for "install telnet" plus your distribution's name (e.g., "install telnet Arch Linux").

Verifying Telnet Installation

After installation, type telnet in your terminal and press Enter. If the installation was successful, you should see the telnet command prompt. If you still get the error, double-check the installation steps or consult your distribution's documentation.

Using Telnet (with caution!)

Once telnet is installed, you can connect to a remote host using the following command:

telnet <hostname or IP address> <port number>

Replace <hostname or IP address> with the address of the remote host and <port number> with the port number (usually 23 for telnet). Remember that using telnet exposes you to significant security risks.

Alternatives and Best Practices

Again, we strongly emphasize the importance of using secure alternatives like SSH. SSH provides encryption and authentication, protecting your connection from eavesdropping and unauthorized access. Invest time in learning SSH; it's a valuable skill for anyone working with Linux or other networked systems.

This article provided a detailed explanation of how to deal with the "-bash: telnet: command not found" error and the crucial importance of prioritizing secure alternatives like SSH for remote access. Remember, security should always be your top priority when working with network connections.