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Why is it that Vista comes with telnet disabled?
If i enable it, is it a potential risk?
Also, in the list there is "telnet client" and "telnet server". I'm wondering what's the difference between enabling each of them?
Pacerier
Posted 2011-07-06T09:53:27.837
Reputation: 22 232
6
Telnet is a protocol that allows one computer to execute a text terminal on another. It's just a connection that transfers text from one to the other computer.
The Telnet server will listen for incoming connections into YOUR COMPUTER. Mostly you will be unaffected since you will likely be behind a little SOHO router, and those don't just let things through like that.
The Telnet client will be installed as a tool for usage in the cmd. If you open the command prompt, you can then type "telnet <server>", replacing <server> with a server name.
Today this is absolutely not used anymore to administer servers and other PCs, since Telnet is insecure. It might be used in very small private networks though.
Telnet is still used on Internet Bulletin Board Systems. These are old forums that are text-only and can only be navigated using the keyboard.
sinni800
Posted 2011-07-06T09:53:27.837
Reputation: 3 048
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telnet is not encrypted, your password and all other data will be transmitted as clear text. "telnet server" means, that windows will listen on port 23 for incoming connections allowing users to login (and allowing non-users try to mess with your computer -> potential risk). I'm not sure what "telnet client" means in this context, but i guess the windows firewall will accept outgoing connections on port 23.
Don't use telnet unless you really need to. Use ssh instead (outgoing). For incoming connections see http://en.wikipedia.org/wiki/Comparison_of_SSH_servers
trurl
Posted 2011-07-06T09:53:27.837
Reputation: 2 102
if i do not do any data transfer, but simply open/enable my telnet client, is it a security risk? (i'm not afraid that people will steal the messages that i've sent.. rather i'm afraid that ppl could use this "backdoor" to whack my com) – Pacerier – 2011-07-06T10:53:17.363
No, this is not a security risk if you only enable the client. The server though will give you no advantage other than that you can access your cmd (commandline) from outside. And even then, as I said, you won't be able to access it from outside your local network without forwarding ports on your router (if you have one!) – sinni800 – 2011-07-06T10:59:20.197
Short: yes. Unlikely, but possible. 1) Unsafe passwords ("letmein"), 2) faulty implementation of the telnet server. – trurl – 2011-07-06T11:06:08.593
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We don't have telnet servers, because as already stated it's a clear text protocol. However we do use telnet client for line of sight testing and to help diagnose network connection problems. A telnet client is a simple and straight forward tool to 'check' if a particular port is available on a target server ie "telnet ".
JJ Smith
Posted 2011-07-06T09:53:27.837
Reputation: 1
Please read the question again carefully. Your answer does not answer the original question. – DavidPostill – 2017-01-13T13:22:34.753
so are there any free <server> that i could play telnet around with? – Pacerier – 2011-07-06T10:38:37.657
Theres Bulletin Board Systems that are freely accessible like Synchronet. Try this hostname after the telnet command: vert.synchro.net. You wont find any servers to freely administrate though ;P – sinni800 – 2011-07-06T10:57:24.817
1The telnet client is also useful in case you want to test manually one of the text based protocols like HTTP/POP3/SMTP. – Robert – 2011-07-06T12:54:57.603