CentOS server not accepting Telnet requests

Azzath · 05-29-2007, 08:00 AM

Hi Guys,
I have a CentOS 5.0 server newly installed and trying to configure telnet on it.
I have done the following already

Code:

0n the xinetd.d/telnet file

# default: on
# description: The telnet server serves telnet sessions; it uses \
# unencrypted username/password pairs for authentication.
service telnet
{
disable = No //Done this
flags = REUSE
socket_type = stream 
wait = no
user = root
server = /usr/sbin/in.telnetd
log_on_failure += USERID
}

Then I have started the vsftpd deamon

Code:

/etc/init.d/vsftpd start

Then

Code:

/etc/init.d/xinted reload

When I telnet my server I get this Error..

Code:

"Unencrypted connection refused. Goodbye".

I have read previous threads and cannot find a solution from them. Could someone please help me to solve this issue.

PS:I have managed to set up telnet on CentOS 3.4 and FC 5 and works fine.

Thank you in-advance,
Best Regards,
A

.

b0uncer · 05-29-2007, 08:04 AM

Use SSH2 instead if you can, as far as I understand it's (a lot) more secure than telnet. Especially if you ever planned to use passwords..

The error message seems to tell that the server won't allow unencrypted connections (whatever it means in this case) and that you are trying to establish an unencrypted connection, and so it fails. Solution: either make your server accept unencrypted connections too (not wise I'm afraid, or safe) or make your client connect with encryption..

Azzath · 05-29-2007, 09:33 AM

You mean to use a telnet client for windows such as putty to use SSH2/SSH? Whats the command like to telnet using SSH2 from a UNIX machine to another UNIX machine?

Thanks for your reply b0uncer.

Any more answers welcome.

Thank you in-advance,
Regards,
A.

mmn357157 · 05-29-2007, 10:27 AM

run the following command and check the output

Code:

# chkconfig --list | grep telnet

if its something like this

Code:

ekrb5-telnet: on
krb5-telnet: on
telnet: on
telnetd: on

You can turn off kerbarose enabled services by

Code:

# chkconfig ekrb5-telnet off
# chkconfig krb5-telnet off

there is a conflict occures when all these services are enabled and your request will probably deny.

Also, try using SSH instead of telnet. its quiet easy to configure and use.
more at: http://www.linuxhomenetworking.com/w...d_File_Copying

Azzath · 05-30-2007, 04:07 AM

Using SSH2 I could Telnet to the Server.

@mmn357157:
Only ekrb5-telnet: on
krb5-telnet: on
was on.

Thanks Guys for all your help

Best Regards,
Azzath.

tuewru · 02-20-2010, 02:08 PM

i have same Azzath's problem
I use Centos OS v5
I can't telnet into virtual server running Centos OS, but i can use SSH that connect to virtual server running Centos OS

I want to telnet into Centos, although SSH ok

Quote:

[root@cisco root]# chkconfig --list |grep telnet
ekrb5-telnet: off
krb5-telnet: off
telnet: on

Quote:

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2010-02-20 11:48 EST
Interesting ports on cisco (127.0.0.1):
Not shown: 1673 closed ports
PORT STATE SERVICE
22/tcp open ssh
23/tcp open telnet
25/tcp open smtp
111/tcp open rpcbind
631/tcp open ipp
737/tcp open unknown
742/tcp open netrcs

Quote:

# default: on
# description: The telnet server serves telnet sessions; it uses \
# unencrypted username/password pairs for authentication.
service telnet
{
disable = no
flags = REUSE
socket_type = stream
wait = no
user = root
server = /usr/sbin/in.telnetd
log_on_failure += USERID

Please help me

bathory · 02-20-2010, 02:53 PM

Hi,

You should start a new thread describing your problem and not a 3ys old one.
Anyways since port 23 is open from localhost, are you sure it's not a firewall problem?

tuewru · 02-21-2010, 04:19 AM

Quote:

Originally Posted by bathory

Hi,

You should start a new thread describing your problem and not a 3ys old one.
Anyways since port 23 is open from localhost, are you sure it's not a firewall problem?

thanks bathory
In Centos OS, I allowed port 23 (Telnet) in Firewall configuration option
In Windows Firewall of Window OS , it exceptions port 23
Finally :

Quote:

C:\Documents and Settings\AdminCisco>telnet 192.168.1.5
Connecting To 192.168.1.5...Could not open connection to the host, on port 23: Connect failed

192.168.1.5/24 : server Centos v5
192.168.1.200/24 : client Windows OS

bathory · 02-21-2010, 04:43 AM

Can you try from the Centos box and see what you get?

Code:

telnet localhost

tuewru · 02-21-2010, 09:37 AM

Quote:

Originally Posted by bathory

Can you try from the Centos box and see what you get?

Code:

telnet localhost

i try to command "telnet localhost"that you suggestion and result :

Quote:

[root@cisco ~]# telnet localhost
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
telnet: Unable to connect to remote host: Connection refused

thanks you for support me

tuewru · 02-21-2010, 09:48 AM

I solved my problem

I searched Google and found a URL "How to enable telnet server on Centos 5"

Code:

 http://www.lecuong.info/How-to-enable-telnet-server-on-Centos-5/

I try command

Quote:

[root@lecuong ~]# /etc/init.d/xinetd restart

and i successful
I can telnet localhost and can telnet my virtual machine running Centos 5

Thanks all people for support me
I'm very happy