Difference between Telnet and SSH

In the past, both Telnet and Secure Shell were frequently utilized to access distant servers. Telnet is the initial protocol that was used in 1969 when the internet was initially launched and is still in use today. However, when it is utilized on public networks, it is ineffective because it was built for private networks and lacks security features. SSH (Secure Shell) was created as a replacement for Telnet. Furthermore, remote terminal service (RTS) enables users at one location to communicate with a time-sharing system at a different location as if their keyboard and display were directly attached to the remote system. The primary distinction between Telnet and SSH is that Telnet is a traditional protocol, whereas SSH is a successor for Telnet protocol with expanded functionality.

In this article, you will learn about the difference between Telnet and SSH. But before discussing the differences, you must know about Telnet and SSH with their advantages and disadvantages.

What is Telnet?

TELNET is an abbreviation for "TErminal NETwork". It is a client-server program that enables users to access any app program on a remote system. Telnet's function is to give services to the user on the remote computer system and to transfer the output to the local computer system. It aids in the establishment of a link to a remote system such that the local terminal resembles a terminal in the remote system. Telnet operates on port number 23.

Telnet is an excellent tool for testing or troubleshooting remote web or mail servers and remote access to MUDs and reliable internal networks.

How does Telnet work?

Telnet offers users a bidirectional interactive text-oriented communication system that uses an 8-byte virtual terminal connection. User data is interpolated in-band with telnet control information through TCP. It was widely utilized on a terminal to perform operations remotely.

The user makes the connection to the server via the Telnet protocol, which is entered into a command prompt using the following syntax: telnet hostname port. After that, the user runs commands on the server by typing particular commands into the Telnet prompt. The user terminates a Telnet command with Telnet to stop a session and turned off.

Advantages and Disadvantages of Telnet

There are various advantages and disadvantages of Telnet. Some advantages and disadvantages of Telnet are as follows:

Advantages

1. It aids in the administration to work over the internet.
2. It is cross-platform compatible.
3. Telnet has user support capabilities.
4. Telnet may be used to transmit and receive computer data through a command.
5. It facilitates task completion on various computers very quickly, connectivity establishment, and significant time savings.

Disadvantages

1. It is a very ineffective protocol on the internet.
2. It is costly due to slow typing speeds.
3. Telnet only allows access to a few servers.
4. Since Telnet is a character-based communication method, it is not possible to use GUI-based tools through Telnet connections. The movement of the cursor and other GUI data cannot be transmitted.
5. User ID and Password may transmit the Telnet Protocol's encryption command.

What is SSH?

SSH is an abbreviation for "Secure Shell". It is a network protocol that is frequently utilized to remotely access and control devices. It is the main protocol for accessing network hardware and servers over the web. It enables you to run commands on a remote system and makes it easier for you to log into another computer over a network. You may transfer the data files from one computer system to another. SSH protocol encrypts the traffic in both directions, which aids you in preventing password theft, trafficking, and sniffing. It also offers some additional features, including public key authentication, server authentication, compression, port forwarding, X11 forwarding, and file transfer.

It also offers remote command execution. When you login into a system, a pseudo-terminal is allocated to your session, which will remain active until you expressly log out. It includes some features such as secure file transfer, port forwarding, and secure command shell.

1. Secure Command Shell

It enables a user to remotely view the directories content, change files, and access custom database apps.

2. Secure Transfer File

It functions as a secure shell protocol subsystem, essentially an additional protocol built over SSH to handle file transfers.

3. Port Forwarding

It is also known as tunnelling and offers minimal security for TCP and IP applications.

SSH Protocol Layers

SSH protocol mainly contains three types of layers. These are as follows:

1. Transport Layer

It enables secure communication between the client and server, monitors data encryption and decryption, and secures the connection's integrity. It also carried data caching and compression.

2. Authentication Layer

It performs the client authentication process.

3. Connection Layer

It handles the communication channels after the authentication.

Advantages and Disadvantages of SSH

There are various advantages and disadvantages of SSH. Some advantages and disadvantages of SSH are as follows:

Advantages

1. It allows you to safely tunnel insecure programs such as SMTP, IMAP, POP3, and CVS.
2. It permits users to remotely inspect the directory's content, change files, and access custom database apps.
3. It is free to use for non-commercial purposes.
4. It enables users to log onto another machine over an unsafe network safely.
5. It provides strong authentication and secure communication via unsafe channels.
6. It may provide numerous services over the same connection.

Disadvantages

1. It is not designed to send cursor or GUI movement information.
2. It does not provide security against Trojan horses or viruses.
3. It is unable to resolve all TCP issues because TCP runs behind SSH.
4. It may not protect user systems from attacks carried out via other protocols.
5. It's not a safe protocol.

Key Differences between Telnet and SSH

Here, you will learn about the key differences between Telnet and SSH. Some of the main differences between Telnet and SSH are as follows:

1. Telnet and SSH protocols both serve the same goal and allow communication to the remote server. However, Telnet is a conventional protocol that is still utilized in several apps. In contrast, SSH is a replacement for Telnet with some additional functionality.
2. Telnet is the conventional TCP and IP protocol for virtual terminal service. In contrast, SSH is a program that allows you to login into another computer over a network and executes instructions in a remote system.
3. Telnet protocol uses port number 23, which was mainly designed for local area networks. In contrast, SSH runs on port number 22 by default.
4. Telnet sends the data in plain text, making it vulnerable to security attacks. In contrast, SSH encrypts transferred data, so a security breach doesn't likely occur.
5. Telnet operates with a private network. In contrast, the SSH protocol performs with a public network.
6. SSH is more secure and comes with additional security features. In contrast, Telnet does not offer any security features.
7. The Telnet protocol is supported by Linux and Windows operating systems. In contrast, the SSH protocol is supported by all main operating systems.
8. Telnet bandwidth usage is low. In contrast, SSH bandwidth usage is high.
9. Telnet protocol doesn't use any authentication. In contrast, SSH utilizes a public key for authentication.

Head-to-head comparison between Telnet and SSH

Here, you will learn the head-to-head comparisons between Telnet and SSH. The main differences between Telnet and SSH are as follows:

Conclusion

SSH is a better option than Telnet in terms of security. Telnet does not offer much security, although it is still commonly used today. However, both Telnet and SSH may be utilized to transfer data to remote servers. Hence, the SSH protocol is strongly recommended.