How to Telnet with Windows XP :

How to Telnet with Windows XP :
The gem is telnet. To get help on Windows type
C:\>telnet /?
In cmd (command prompt).
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1. What is a Port on a computer? Port is like where things can go in and/or out of a computer. Some ports are easy to understand, like keyboard, monitor, printer and modem; Others are virtual (created by software). When modem port of (or LAN or ISDN or DSL) is connected to the Internet, your computer has the ability to open or close any of over 65,000 different virtual ports, and has the ability to connect to any of these on another computer - if it is running that port, and if a firewall doesn’t block it.

2. How do you address a computer over the Internet? There are two ways: by number or by name.
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The simplest use of telnet is to log into a remote computer. Give the
command:
C:/>telnet targetcomputer.com (substituting the name of the computer you want to telnet into for targetcomputer.com)
If this computer is set up to let people log into accounts, you may
get the message:
login:
Type your user name here, making sure to be exact. You can't swap between lower case and capital letters. For example, user name Guest is not the same as guest.
If you don't know your user name and password, that means whoever runs that computer didn't give you an account and doesn't want you to log on.

Then cometh the message:
Password:
Again, be exact in typing in your password.
What if this doesn't work?
That is usually because people try to telnet into a computer, or a port on a
computer that is set up to refuse telnet connections. Here's what it
might look like when a computer refuses a telnet connection:
C:\ >telnet 10.0.0.3
Connecting To 10.0.0.3...Could not open connection to the host, on port 23. A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
Or you might see:
C:\ >telnet abcd.com
Connecting To abcd.com...Could not open connection to the host, on port 23.
No connection could be made because the target machine actively
refused it.
N.B: If you just give the telnet command without giving a port number, it
will automatically try to connect on port 23, which sometimes runs a
telnet server.
Windows computer has a telnet client program, meaning it will let ye telnet out of it. However you have to install a telnet server before anyone could Telnet into port 23 on your
computer.

If Telnet failed to connect, possibly the computer you were trying to telnet into was down or just plain no longer in existence or may be the people who run that computer don't want you to telnet into it.
How to Telnet into a Shell Account :
Even though you can't telnet into an account inside some computer, often you can get some information back or get that computer to do something interesting for you. Yep! you can get a telnet connection to succeed -without doing anything illegal ,almost any computer, even if you don't have permission to log in. There are many legal things you can do to many randomly chosen computers with telnet. For example:
C:/telnet freeshell.org 22
SSH-1.99-OpenSSH_3.4p1
That tells us the target computer is running an SSH server, which enables encrypted connections between computers. If you want to SSH into an account there, you can get a shell account for free at
http://freeshell.org/ You can get a free SSH client program from
http://winfiles.com/
One reason most Hackers have shell accounts on Internet servers is, because you can meet the real hackers there. When you've logged in, give the command w or who. That gives a list of user names n u can talk to other users with tht talk command. Another fun thing, if your shell account allows it, is to give the command
ps -auxww
It might tell you what commands and processes other users are running. Ask other users what they are doing and they might teach you something.
But be careful not to be a victim of technology!
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Also Your online provider might stop you making telnet probes of other computers. The solution is to get a local online provider and make friends with the people who run it, and convince them you are just doing harmless, legal explorations.[some of other ways r also ther].

Sometimes a port is running an interesting program, but a firewall won't let you in. For example, X.X.X.X(IP address) ,a computer on LAN, runs an email sending program, (sendmail working together with Postfix, and using Kmail to compose emails). User can use it from an account inside that IP address to send emails with headers that hide from where user send things.
If user try to telnet to this email program from outside this computer,
here's what happens:
C:\>telnet X.X.X.X 25
Connecting To X.X.X.X...Could not open connection to the host, on
port 25.
No connection could be made because the target machine actively
refused it.
However, if user log into an account on X.X.X.X and then telnet from
inside to port 25, here's what I get:
Last login: Sat Nov 11 12:59:59 2008 from X.X.X.X
Have a lot of fun...
ani@test-box:~> telnet localhost 25
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1... [ani's note: 127.0.0.1 is the numerical
address meaning localhost, the same computer you are logged into]
Connected to localhost.
Escape character is '^]'.
220 test-box.local ESMTP Postfix
The reason to keep this port 25 hidden behind a firewall is to keep
people from using it to try to break in or to forge email.
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All about headers? It's at the beginning of an email that may - or may not - tell you a lot about
where it came from and when. To see full headers, in Outlook click
view -> full headers.