SSH and telnet both are networking protocols that are used to access and manage remote systems. But the question arises here what is it that makes them different and when is it better to use over the other? How is SSH different from telnet? In this blog, we will get to know the difference between SSH and telnet. Before moving through the details of both these two protocols we should know more about these two protocols.
SSH and telnet both are seven-layer application protocols and both use the transmission control protocol (TCP) at the transport layer. To access the machine at remote location networking provide various programs among which telnet and SSH are the primary client-server application programs. It uses the remote terminal service that allows the user at one end to interact with the remote machine at another site. As if the display and users’ keyboards are connected directly to the remote machine system.
What is telnet?
The word Telnet stands for Terminal network and it is as old as the internet. In 1969 it was launched along with the net that is used to this day. Telecommunication and network (telnet) and secure shell (SSH) are the primary client-server applications that allow the users to link with remote systems.
Telnet is the standard transmission control protocol (TCP/IP) that is designed for virtual terminal service. Telnet allows establishing a connection with a remote system in such a way it looks like a local system. It helps the users to access the device by telnetting to the Internet protocol address of a remote system. Users have the access to go through any application on a remote computer system. In other words, telnet is a two-way, text-based communication channel between two systems.
What is SSH?
The SSH stands for secure socket shell that is widely used to access and manage a device remotely. It is the major protocol to access the network servers and devices over the internet. The primary function of both telnet and SSH are the same but the SSH does more securely. SSH protocols provide more security even on unsecured networks, and eliminate telnet vulnerabilities.
It helps you to log in to another computer and gives you access to move files from one device to another device, execute commands, and many more. In addition, SSH is more secure in such a way it encrypts traffic in both directions, which helps to protect the system from sniffing, password hackers, and trafficking. Note that you are familiar with these two protocols. Now we discuss the purpose of this blog (Telnet vs SSH comparison) in the following section.
SSH vs Telnet comparison chart:
Although SSH and the telnet have some similarities these two have many differences among them. The most important is that the socket shell is more secure than the telnet. SSH now completely replaces the telnet in everyday use. telnet use port no 23 while the SSH use port 22 by default. Telnet transfers data as text communication, in contrast, SSH can encrypt traffic in both directions.
|definition||secure shell is a program in which log in into another computer over a network and then execute programs and send files to another device.||It is the abbreviation of telecommunication and networking and it’s the networking protocol; best of UNIX over the local area network.|
|security||Highly secure. Data cannot be easily interrupted by hackers.||Less secure than SSH, and have many vulnerabilities, and is easily attacked by hackers.|
|operation||It uses port no 22 by default. Port numbers are very easy to change.||telnet use port no 23 its best work with local area networks.|
|Validation||Use public key verification.||No verification method|
|Operating systems||All operating system||Linux and Windows|
|formats||Data is transferred in coded format via a secure channel||Data is transferred as simple communication text-based|
|preference||SSH is good for public networks.||telnet is less secure than SSH so, private networks are preferable for telnet.|
What are the main differences?
Although there are many similarities there are many differences that separate these two protocols. The primary difference is that SSH is more secure than telnet. On the base of this reason, we can say SSH replaces the telnet in everyday use. Let’s discuss the comparison chart between SSH and telnet in detail.
SSH operates by making a secure connection with port no 22 although you can change the port number. With the key-based authentication, after the client checks the client sever a key is generated and sent to both the server and the client. This session key encodes the traffic for ongoing sessions. Using the key pair server verifies the clients. Once the client is the end to end encrypted a secure connection is established and then the system is finally able to exchange data.
For telnet, a server application is required on the remote system. And the client application is installed on the local system. telnet use port 23 and TCP protocol for establishing a connection with a remote system. After that, this system acts as a telnet server and executes the commands. Commands are executed in the form of NVT (network virtual terminal), received and interrupted by the server, and then sent to the suitable application.
SSH uses public key authentication which is the most secure SSH authentication. When the SSH pair key is generated, the client keeps the private key while the public key is sent to the server. If the client tries to access the server, then the server verifies the cline by comparing the pair keys if the keys match, then a secure connection is established. Telnet does not use any authentication keys when establishing a connection.
Telnet does not use any security system when sending the data. This default makes it highly vulnerable. As compared to telnet SSH is highly secure. SSH uses the pairing key for authentication. It is extremely hard to decrypt and read the data. This is a highly secure way of transferring data even over unsecured networks.
Telnet transfers in the form of text using the network virtual terminal.SSH transfers data in the form of encryption via a secure connection.
We all know that SSH is more secure than telnet which makes it useable in all cases even in public networks. As compared to telnet SSH provides more functionality like port forwarding and file transfer in a secure way. However, there are two cases in which telnet is preferable over SSH,
- When using the system or device that cannot support SSH
- When you are working on trusted networks like LANs, you can use the telnet
In these situations, lack of security in telnet is not an issue and the plus n\benefits is that lower usage of bandwidth counts.
When to use SSH and Telnet?
SSH is a highly secure network, you can choose SSH whenever you want to connect to a remote device through the internet. It provides more functions than telnet like port forwarding and file transfer.
But there are two cases where telnet is recommended over SSH,
- When using the system or device that cannot support SSH
- When you are working on trusted networks like LANs that are not connected to the internet you can use the telnet.
Important telnet and SSH commands:
Here are given some important telnet commands such as,
- Open: open the host port number to establish a connection with the host.
- Close: it helps to close the telnet connection with the host.
- Quit: helps close the existing telnet connections
- Status: it talks about whether the telnet client is connected or not.
- Timing marks: It defines the timing marks.
- Terminal speed: setting the terminal speed and type.
Here are some important SSH commands such as
- ls: show the list of names of files.
- cd: it helps to change the directory.
- mkdir: new folders are made in the directory.
- touch: allows removing a file.
What are the advantages and disadvantages of telnet?
- Telnet supports user authentication.
- It is used to send and receive information.
- Remote login saved your time
- Collaboration of multiple users.
- telnet is used in all types of operating systems.
- All the servers and network clients use the NVT (network virtual terminal)
- It is not an ideal protocol for transmitting GUI information.
- Dynamic ports are not supported in telnet.
- It is text-based communication that displays only numbers and text, not graphics or colors.
- Telnet lacks the security data it allows hackers to hack the login credentials and sensitive information.
What are the advantages and disadvantages of SSH?
- It provides privacy through a strong connection
- Tunneling of port works very effectively via a simple VPN.
- SSH protects from DNS spoofing, IP address spoofing, and data manipulation.
- Working on SSH requires technical knowledge.
- It has no native GUI.
- This protocol does not protect from viruses and trojan horses.
Let me sum up, both are network protocols that can help to manage and access devices remotely. While SSH is more secure than telnet and provides better functionalities than telnet. But telnet is still used in some situations.