Hello friend and welcome to PCmoment.
Of course, telnet/ftp are not secure until you can get in the device and configure it for usernames/passwords/SSH/sftp. BTW - It would be nice if Apple would enhance Terminal to enable a ZTerm/PuTTY type virtual serial port for accessing Cisco devices.
You will learn about telnet command prompt today.
Not only that, you will see the uses of telnet, how to enable telnet on different O.S, the common syntax used to telnet.
There are some better alternatives to telnet if you need them, we will discuss that too.
Without any further intro, let us get to the topic by first explaining what telnet is.
What Is Telnet
Telnet is one of the protocols in a TCP/IP network.
This protocol allows a user in a different location to connect to another computer or server in another location through the internet.
You can easily test if a service is enabled on the remote computer you are connected to or not.
Also, you can use telnet to know is a port is open or not on the remote computer.
The TCP/IP port used to initiate the communication is port 23.
In older versions of windows and Mac, Telnet is readily available. However, recent versions of these O.S require that you manually enable telnet.
How to open telnet is fully discussed below.
Uses Of Telnet Command Prompt
Telnet is used to connect to a remote Server
Use to connect to a remote computer
Also, it is used to test a service on another machine
Use to test if a port is open.
And also used to access programs on a remote machine.
How To Enable/Install Telnet
On a Windows computer, open Control Panel by clicking the Start button.
Or you search Control Panel in the search bar on your taskbar.
Click on Turn Windows features on or off located at the left-hand side of the Control Panel page.
You will be asked to sign in with an admin username and password if you haven’t already.
A Windows box will open and from there you will select Telnet Client from this list.
Click Ok to install to make the telnet client available on your command prompt.
How To Enable Telnet On Mac
Please note that Mac O.S versions older than Mac Sierra 10.13 have telnet enabled by default.
Download Telnet For Mac
So you should only do this step if you O.S is Mac Sierra 10.13 and above.
Unlike windows, copy and paste this code into the terminal: /usr/bin/ruby -e “$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)”
The code will install Homebrew on your computer.
Then you run this code in the terminal also to install telnet: brew install telnet
And with that, you should have telnet on your Macintosh computer.
How To Telnet Command Prompt
It is important that you first install telnet on the windows computer or Mac before you try using telnet command prompt.
Telnet Mac Os
This is the easiest part of the whole process and also, it is the main part of this article.
So here it is my friend:
Open Command prompt as you normally do, either search or type cmd in Start.
When the cmd prompt has opened, type telnet then you press the Enter key.
You will see Welcome to the Microsoft telnet client displayed on the command prompt.
And the status bar of the command prompt will show telnet.
Telnet Command On Windows – Syntax
Syntax to connect to remote computer/server
telnet 10.10.10.18 25
where 10.10.10.18 is the IP address of the host, computer /server and…
25 is the port number you which to connect.
In some other cases, you can just type the URL of the host instead of the IP address.
Syntax Display Help In Telnet Command Prompt
The simple syntax is ?
Just the question mark will do the job and this help will leave you will many syntaxes to play with.
Syntax to quit telnet
telnet command prompt allows a shortcut to all its syntax.
So, the syntax to quit telnet is quit and q for short.
Syntax to Open Connection To Remote Host
Type o 172.18.21.55 44
Telnet will open connection to the computer with that IP using port 44.
Please note that o is the short form of open.
Syntax to Close Existing Connection
Type c 172.18.21.55 44
You can use a hostname instead of the IP address.
Syntax To View Settings on A Remote Host
Type display and all the current settings on the telnet-ed host will show.
Mac Telnet Not Found
Common Port To Test On Telnet
Port 3389
To test the remote computer.
Port 443
To test the HTTPS of the computer for secure internet services.
Port 21
File Transfer protocol, FTP
Port 25
SMTP, Simple Mail Transfer Protocol.
Port 80
To test the HTTPS of the computer for non-secure internet services.
Port 110
To test the incoming mail. POP
Port 143
To test the incoming mail. IMAP
Port 587
To test the incoming mail. SMTP alternative.
Download Telnet In Mac Terminal Commands Download
Telnet Command Prompt Alternatives
There are many alternatives to telnet and few of those are:
PowerShell
It is only available in windows and unlike telnet that you have to install before usage, PowerShell is readily available on Windows PC starting from Windows 7.
Netcat
Just on Linux and Mac, Netcat helps to connect to the network.
Thank you for reading to the end.
I hope you find what you were looking for before you stumbled on this page.
If not, send me a mail using the contact page and I will respond ASAP.
Please help to share the knowledge, some of your friends might need to know this telnet command prompt tricks.
Mac Telnet Port
Image Credits: Morteza