5.1 GUI or CLI

To use Telnet, you must have Telnet software installed on a remote device

Most current OSs have a Telnet client. In order to establish a remote connection, a Telnet server must be installed and running. Some familiar Telnet servers are Putty, 3cdaemon, and TeraTerm, to name a few. Telnet establishes a connection by using TCP port 23 by default.

Telnet allows the user to perform several tasks locally except

physically boot up a sever

The most common method to access the CLI is to connect a direct serial/Universal Serial Bus (USB) connection to the switch's console port. However, if you are not nearby and need to connect to a device remotely, you would use Telnet or Secure Shell (SSH).

Telnet is a network protocol that permits a user to communicate with a remote machine. It is a virtual terminal protocol used typically by a network professional to manage and access devices remotely. An administrator can connect to the device by telnetting to the remote device's hostname or IP address.

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Using an OS with a GUI is as simple as clicking an icon or dragging the mouse. There is no need to have prior knowledge of commands to accomplish a task. Most GUI operating systems come with numerous tools to aid in managing. For example, with a text editor's assistance, a user can manipulate text and programming languages. Furthermore, a menu offers a list of programs and applications a user can choose to run. Windows and Linux both have a GUI. However, most Linux professionals are very well versed in using the CLI.

Similar to Telnet

a user connecting to a remote device must have an SSH client installed. A SSH server must be running and installed on a remote machine. SSH establishes a connection by using TCP port 22 by default.

command interpreters

can be used for several purposes. Command interpreters are used in scientific environments and on devices that may not have the resources to support a GUI. Command interpreters also work well for a user with disabilities because the instructions and commands can be displayed using braille.

Telnet does not have to run on a computer; it can run on a

dumb terminal

Secure Shell (SSH) is very secure because the data is

encrypted

Telnet is very fast because it only sends text and not

graphics

Telnet can be used to connect to several network devices except a

hub

One of the ultimate drawbacks of using Telnet is that all data,

including passwords and usernames, is sent in clear text, which is a possible security risk. This is the primary reason why Telnet is seldom used today and is being substituted by a much secure protocol called SSH.

SSH

is a network protocol used to manage and access a network device remotely. SSH and Telnet's primary difference is that SSH uses encryption; therefore, all the information sent over the network is secure from snooping or eavesdropping. SSH uses public-key cryptography to make sure all transmissions are protected.

CLI operating system

is more challenging to navigate than a GUI operating system simply because the user must be familiar with the commands. In most instances, skilled networking professionals use CLI to complete a task while a novice can operate the GUI.

Character User Interface, Command language interpreter, and console user interface are

just a few of the names used to describe a CLI. A Character User Interface was used on older computers; it is not very customizable and complicated to operate. The Character User Interface was the forerunner to the GUI and used in OS like Microsoft Disk Operating System (MS-DOS).

OS

of a device is simply the software interface between the user and the hardware components. The most common categories of OSs are Windows, Linux, and Mac. Most OSs include both GUI and CLI to interact with the hardware. However, some OSs use only a CLI. When using a command-line OS, the user must write specific commands to perform various tasks.

The CLI is the primary interface for managing, configuring, and monitoring network devices

such as switches and routers. The CLI allows you to enter specific configuration commands and receive an output from the router or a switch. The network device's OS, sometimes known as the IOS, recognizes the command you enter and performs several services on the device, including configuring, monitoring, and maintenance.

GUI Operating System

uses graphics made up of images and icons that allow a user to perform tasks without any prior knowledge of commands.