topic Re: Telnet problem in RHEL5 in Operating System - Linux

Telnet problem in RHEL5

Yaboto — Mon, 08 Feb 2010 10:42:41 GMT

Please help me telnet to my RHEL5.

I change disable=yes to disable=no in the /etc/xinetd/telnet and restart the xinetd service successfully but I am still getting the following error message:

C:\Users\laptop>telnet 10.7.2.103
Connecting To 10.7.2.103...Could not open connection to the host, on port 23: Connec
t failed

Regards,
Berenger

Re: Telnet problem in RHEL5

Horia Chirculescu — Mon, 08 Feb 2010 11:26:04 GMT

Go first to your linux server and issue a telnet localhost

This would confirm you that everything is working as expected.

If it is working, check your firewall rules.

Horia

Re: Telnet problem in RHEL5

Yaboto — Mon, 08 Feb 2010 11:38:51 GMT

Here is what I get when I telnet localhost:

[root@blc3 ~]#
[root@blc3 ~]# 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
[root@blc3 ~]#

Please Advice

Re: Telnet problem in RHEL5

Horia Chirculescu — Mon, 08 Feb 2010 11:54:03 GMT

Seems that telnet service is not enabled

Use this:

chkconfig --list | grep telnet

to find out telnet's status.

To enable telnet, use:

chkconfig telnet on

after that command, the:

chkconfig --list | grep telnet

should show you that telnet is enabled (on).

Horia.

Re: Telnet problem in RHEL5

Yaboto — Mon, 08 Feb 2010 12:38:01 GMT

rsync: off
tcpmux-server: off
telnet: on
tftp: off
time-dgram: off
time-stream: off
[root@blc3 ~]# chkconfig --list | telnet
telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
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telnet> ?Invalid command
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telnet> ?Invalid command
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telnet> ?Invalid command
telnet> ?Invalid command
telnet> ?Invalid command
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telnet> telnet> ?Invalid command
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telnet> [root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]# chkconfig --list | grep telnet
ekrb5-telnet: on
krb5-telnet: on
telnet: on
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]# chkconfig --list | vsftpd
[root@blc3 ~]# chkconfig --list | grep vsftpd
vsftpd 0:off 1:off 2:on 3:on 4:on 5:on 6:off
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]# chkconfig --list | grep telnet
ekrb5-telnet: on
krb5-telnet: on
telnet: on
[root@blc3 ~]# chkconfig --list | grep telnetd
[root@blc3 ~]# chkconfig --list | grep telnet
ekrb5-telnet: on
krb5-telnet: on
telnet: on
[root@blc3 ~]# chkconfig telnet off
[root@blc3 ~]# chkconfig --list | grep telnet
ekrb5-telnet: on
krb5-telnet: on
telnet: off
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]# chkconfig --list | grep telnet
ekrb5-telnet: on
krb5-telnet: on
telnet: off
[root@blc3 ~]# chkconfig telnet on
[root@blc3 ~]# chkconfig telnet on
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
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[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
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[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#
[root@blc3 ~]#

[root@blc3 ~]#
[root@blc3 ~]# chkconfig --list | grep telnet
ekrb5-telnet: on
krb5-telnet: on
telnet: on
[root@blc3 ~]#
[root@blc3 ~]# 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
[root@blc3 ~]#

Please Advice

Re: Telnet problem in RHEL5

Horia Chirculescu — Mon, 08 Feb 2010 13:03:17 GMT

>[root@blc3 ~]# chkconfig --list | grep telnet
ekrb5-telnet: on
krb5-telnet: on
telnet: on

Stop the krb5 servers:

chkconfig ekrb5-telnet off
chkconfig krb5-telnet off
service ekrb5-telnet stop
service krb5-telnet stop

Start the telnet service:

service telnet start

Horia.

Re: Telnet problem in RHEL5

Horia Chirculescu — Mon, 08 Feb 2010 13:32:02 GMT

In order to overcome security issues, you should use SSH to access your server(s).

If you use windows on your laptop, a free ssh client would be putty:

http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

Horia.

Re: Telnet problem in RHEL5

AnthonySN — Mon, 08 Feb 2010 14:45:29 GMT

using ssh is the best option to connect your server since telnet sends password in clear text format and can be easily hacked.
that is the reason it is disabled by default.
as suggested use putty from a windows environment.

Re: Telnet problem in RHEL5

dirk dierickx — Tue, 09 Feb 2010 06:46:14 GMT

do _NOT_ use telnet, if for some reason you still need this protocol left over from the 80s (hence it's not even installed by default anymore, since years. ssh started shipping by default in RH7, that was somewhere close to 1997!!), well i guess that is your insecure choice then.

have you tried to open the telnet port in the firewall, if you have a firewall active, that is.