When I try to telnet to my Linux box I get ok on 1 of the tty sessions. Then when I try to telnet to one of the systems within the network I keep getting the msg "telnet: tcp/telnet: unknown service" I have been telnetting in ok for over 2 years, then all the sudden this error msg appear. I have checked the /etc/services file and the telnet service is not # out. Any suggestions....

Check the /etc/xinet.d/ directory for a file called 'telnet'
open it make sure it doesn't say
disable = yes

after that restart xinetd


If this telnet problem started happening after an upgrade than you can be sure this was the problem.

If this problem is still occurring tell us.

with disable = yes, you'll get a denied message, not that error.

In the /etc directory there is no dir called /xinet.d However there is a file inetd.conf which you may be referring. There is no file called "telnet". I am using V6.2 of Red Hat. I recently installed and ran I program called "logcheck". I ran this command :
"rpm -i ftp//linuxserv.uga.edu/pub/unix/linux/redhat/contrib/libc6/
i386/logcheck-1.1.1-1.i386.rpm"

It installed and ran ok. I had it running for @ 2 days before I encountered the telnet/tcp error msg.

Maybe this is not a telnet problem - could it be a tcp configuration
problem? Any help....

Also I can't find any file simply called telnet. I ran :
"find / *telnet*"
and it came up blank...

Major drama here...

Also this may be of help. When I run the "netstat -na" it gives me the service telnet in a state=listen. The tcp service state=7 What does this tell me....I am not sure of this state=7.....Help....

I'm running RH 7.1 so this may not be a workable command for you, but try

locate telnet

also try using chkconfig --list |less
which will tell you what services are available and which are running. If chkconfig works for you, then try

chkconfig telnet on

(all this must be done as 'su')


man chkconfig

"chkconfig telnet on"
gave me - error reading information on service:No such file or directory

did you do a chkconfig --list ? Telnet is usually listed at the bottom. You should at least be able to see if it's there.

Maybe you need to reinstall telnetd....but I'm guessing and certainly far from the most experienced in this regard.

Telnet was not listed.....plot thickens...
How do I re-install telnetd...?

If you have the RedHat cd's it should be there in the RPMS directory on one of them.

I just want to point out as an aside, telnet is a terrible remote access application, totally insecure and crackable.

I only use ssh, much more secure....OpenSSH should be in the same RPMs directory on one of your cd's.

I totally agree with using telnet. I want to start using SSL. I don't know much about it. I have installed it and run the keygen program and made my own sshd_config file. Now how do I (if you can help) :
[1] Get to it via a Windows machine.
[2] With all these encrypted passwords - how do I actually set the password? Is this done on the Linux side?

Any suggestions is appreciated...

Well, here's how I did it.

Install sshd via rpm -Uvh openssh.<version #>.rpm
chkconfig --level 2345 sshd on
make sure that port 22 is open through the firewall

Then, to connect via a windows machine, you need to get an ssh client for windows. I use PuTTY (do a google search for it: putty ssh). Putty will do both SSH and Telnet. It doesn't need to be installed and it's a tiny little .exe file.

Type in the IP and choose the SSh option, and just use the same user/pass as you would to login to your machine locally.

Works for me!